Spoiler Warning: If you haven't seen Episode III yet, you may not want to read ahead.
Ships Aplenty
During the space battle, when a blue laser beam lances out of the belly bay of a massive Republic Star Destroyer and splits a Banking Clan frigate in two, it unleashes a blossoming explosion with streaming debris. The camera pans along with one sizable chunk as it slams back into the Republic vessel. That is indeed a kitchen sink.
An audio easter egg -- and hallowed tradition of Star Wars -- is the piercing scream affectionately called "the Wilhelm." It's a decades-old audio recording of a very distinctive scream that has become a "pet sound effect" to many sound editors, though Ben Burtt deserves special mention for surreptitiously spreading it through the movies he's worked on. It can be heard shouted by a clone trooper thrown by an exploding weapons emplacement during the opening space battle.
Subtly providing some nice connective tissue to the original trilogy are the designs of the starfighter targeting computers. The display screens in Anakin and Obi-Wan's Jedi fighters very closely resemble those on Darth Vader's TIE fighter, while the little icons lining the screens of the clone fighters look a lot like those found on the X-wings.
There's so much happening high above Coruscant that it's hard to single out one spectacle not to miss. There's a very intriguing tangle that has a triangular Republic destroyer caught within the arms of a massive ring-shaped Trade Federation battleship. It's hard to tell what's happening here: perhaps the Federation ship has somehow captured the Republic vessel in its clutches. According to the Animatics Department that plotted out the space battle, the Republic ship is docked with a captive donut ship, and teams of clone troopers are tearing through the corridors.
It's tiny, but visible enough to send a warm fuzzy through the hearts of original trilogy fans. In the establishing shot of the expansive Senate docking bays, there's a tiny Millennium Falcon easing into frame. And it's not just a non-descript Corellian freighter; it's on good authority -- namely George Lucas -- that this is the infamous hunk-of-junk before it came into the ownership of either Lando Calrissian or Han Solo. Also peculiar about that shot: there are no less than three gleaming Naboo star skiffs parked on the lot. Does Padmé have spares?
Though it's been reported that the Senatorial plotlines of Episode III were all cut out of the film to keep the focus on Anakin's story, almost all of those supporting Senators are still in the film. The starwars.com databank recently added such Senators as Chi Eekway, Terr Taneel, Nee Alavar, Mon Mothma, Giddean Danu, Malé-Dee, Fang Zar, Meena Tills, and Fema Baab to its encyclopedic entries, and they are all on that platform. Watch for them.
Some press outlets have reported that Jar Jar doesn't utter a single word in this film, but he does. Listen closely as the Senators file in behind Palpatine and enter the building. The bungling Gungan accidentally invades Senator Orn Free Taa's personal space, provoking an exchange of "Watch it." "Excuse me."
Expanded universe fans may have had their ears perk up when Obi-Wan gives the single-sentence summary of the Jedi briefing Anakin just missed. He mentions that Master Vos has moved his troops to Boz Pity. That is indeed a reference to Quinlan Vos, who was almost slated to appear in Episode III. Lucas included the comic book Jedi in the script, though his sequence was never filmed.
Opera Cameos
Who's who at the opera! There's many familiar faces to spot at the Galaxies Opera House, though given the exotic -- and sometimes immodestly dressed -- patrons seen milling about, it can be hard to spot them. As Anakin runs up the carpeted staircase, one of the guests he passes is Dannl Faytonni, the human character first played by an unmasked Anthony Daniels in Episode II. The man behind C-3PO gets to show his features once more, if ever so briefly, only this time he's wearing a captain's rank and a tall hat, suggesting he's moved up the social ladder.
Once inside, Anakin weaves through a bustling corridor. Blink, and you'll miss such returning aliens as Horox Ryyder (from Episode I), Greeata and Rystáll (from Episode VI) as well as the most notable cameo. Talking to Senator Chi Eekway is the blue-skinned Baron Papanoida -- cameo appearances for Katie Lucas and her father, writer-director George Lucas. His other daughter, Amanda Lucas, is also in this shot as Senator Terr Taneel.
In the next shot, as Anakin settles into Palpatine's viewing box, take a look at box adjacent to the Chancellor's. It is filled with notable names from Industrial Light & Magic. Seated from left to right (first row) are Visual Effects Producer Jill Brooks, Animation Supervisor Rob Coleman, Visual Effects Producer Janet Lewin, (and back row) Visual Effects Supervisor Roger Guyett, Visual Effects Producer Denise Ream, and Visual Effects Supervisor John Knoll. If you look at the shots that favor Palpatine during his wistful retelling of the Darth Plagueis yarn, you'll see Knoll sitting over his shoulder.
In the same establishing shot of the interior of the Opera House is another Easter Egg strolling down the aisles. Dressed in a long green robe is Hyperspace's Set Diarist and Star Wars Insider columnist Pablo Hidalgo as Janu Godalhi. You can read about how his cameo came to be and see pictures of the shoot in this exclusive Post Production report here.
If you wanted to split hairs about continuity, Coleman, Guyett, Ream, Brooks and Hidalgo are also in the far background of the preceding staircase shot, suggesting that they somehow beat a running Anakin to the inside of the theater.
In the establishing shot of Kashyyyk, the Wookiee aircraft are accompanied by giant dragonfly creatures like can-cells. If you look carefully, they have little alien riders: adventurous Aleenan aliens, the same species as the scrappy Podracer, Ratts Tyerell. Yeehaw!
It gives you an idea of scale if you somehow manage to miss an entire Star Destroyer, but it happens. When the establishing fly-into Kashyyyk ends, parked behind the trees is Yoda's Republic Star Destroyer.
Yoda's not the only Jedi on Kashyyyk. Organizing defenses on the beach is Luminara Unduli, only here she's not played by Mary Oyaya for her single shot. It's Art Department Supervisor Fay David. She had previously played a handmaiden in Episode I and Shaak Ti (in the library scenes) in Episode II.
Some fans think they spot Aurra Sing, the chalk-skinned bald-headed bounty hunter from Episode I, in the sculpted frieze hanging in Palpatine's office. It's not really, but the sculpture is worth taking a look at. It depicts an ancient battle between Jedi and dark side-corrupted creatures and aliens.
There's a lot going on in the brief shot of the dragon pen before Boga comes bounding into frame. There's a little Utai alien luring a dactillion -- a pterodactyl like creature -- to roost with a piece of meat, and a gaunt Utapaun taking a dog-sized spider for a walk.
In the background of the 10th Level, as Obi-Wan whistles for Boga to come and give chase to General Grievous, look in the background. A clone trooper has lost his rifle and is essentially boxing with a battle droid.
If you've seen the fork-wielding Utapaun action figure and were wondering just where it is in the film, you'll have to look quickly. This warrior can be seen riding on the back of a dactillion as the battle erupts on Utapau.