''Star Wars: Episode III'' -- what do we know so far?

Light saber-wielding fanatics aren’t waiting in line yet for ”Star Wars: Episode III.” But that’s only because the final chapter’s release date is still far, far away: May 25, 2005, to be precise. Nonetheless, filming for the still-subtitle-free prequel has started, with stars Hayden Christensen, Natalie Portman, and Ewan McGregor (not to mention Yoda, Chewbacca, R2-D2, and C-3PO) all joining director George Lucas in Sydney, Australia.

One pleasant surprise: The usually-secretive Lucasfilm has been giving fans more access to the shoot than ever, via Hyperspace, a paid subscription service on StarWars.com. Here’s what we know so far (hardcore Jedi Knights should beware of spoilers):

DARTH SIDE Darth Vader-to-be Anakin Skywalker (Christensen) won’t just slip into the dark side of the Force in ”Episode III” — he’ll also plunge headfirst into the 1970s. A shot of Anakin on StarWars.com’s on-set webcam reveals an all-black wardrobe and a distinctly Me Decade hairdo of blond, shoulder-length tresses. The style is apparently meant to bridge the visual gap between the new movie and the first ”Star Wars” (a.k.a. ”Episode IV”), which was filmed in 1977.

And even before he dons Darth’s helmet, Anakin will lose some of his heartthrob looks, thanks to the rigors of fighting in the Clone Wars (which occur off-camera between Episodes ”II” and ”III”). ”He looks quite rugged and weathered… like he’s been around the track a bit,” hairdresser Annette Miles told StarWars.com’s on-set chronicler. Meanwhile, producer Rick McCallum batted down rumors that Christensen will spend only five minutes as Darth Vader in the new film: ”You should know not to believe every rumor your hear. I don’t think you’ll be disappointed,” he told fans in an online chat.

CHEW ON THIS The lovable yet ill-tempered Wookiee known as Chewbacca will not only return in ”Episode III” (after his absence from the first two prequels) — he’ll have an important role. Peter Mayhew, the dude in the furry suit, told a British journalist that the opening scene of the movie is a Wookiee battle sequence that takes place on a never-before-seen planet. More startlingly, Mayhew also said that Chewbacca acts as midwife to Natalie Portman’s Padmé when she gives birth to twins Luke and Leia. We hope he washes his paws first.

MOTHMA PROPHECIES Also returning for ”Episode III” is Mon Mothma, the stately, berobed leader of the Rebel Alliance not seen since ”Return of the Jedi.” In ”Episode III,” the character (played by young Australian newcomer Genevieve O’Reilly — who also had a tiny role in ”The Matrix Reloaded”) will be a Galactic Senator who works alongside Padmé. No word on whether she’ll reprise the immortal Mothma line: ”Many Bothans died to bring us this information.”

AVOID THE DROID By ”Episode IV,” R2-D2 and C-3PO are like a cranky, robotic, long-married couple, but in the first two prequels, the droids are relative strangers. That will finally change in ”Episode III,” which will also replace the mechanical R2-D2 with a digital version in more scenes than before. Droid Unit Supervisor Don Bies (who has the coolest job title ever) promised fans in an online chat that Threepio and Artoo’s ”relationship deepens and blossoms.” Hey, get a room, you two.