They haven't officially announced it yet, but Iron Man 2 is set to start shooting as early as March, at least if you believe the horse's mouth.

Clark Gregg -- who played agent Phil Coulson in the '08 summer blockbuster -- found himself in the unique position of sharing a flight from London to L.A. with the movie's star Robert Downey Jr. as his seatmate.

Gregg, who's a regular on the Julia Louis-Dreyfus sitcom The New Adventures Of Old Christine, has just finished his feature directorial debut -- an adaptation of Choke, from dementoid novelist Chuck Palahniuk.

And he came away pretty much assured of a job once the series goes on hiatus in the spring.

"I'm pretty sure Robert Downey will be in it, and I'm sure Gwyneth (Paltrow) will be in it," Gregg says jokingly. "But I went to a festival in Locarno, Switzerland, where they screened Choke and I went back via London to L.A. to get back to Old Christine by Monday. And Robert Downey was in the seat next to me, and I was trying to milk him for details. 'C'mon man, you've seen the script. Is agent Coulson mentioned in there? And finally he said, 'Yes, there is some Coulson.' "

JUNGLE FEVER: We can hear it now: "Me Tarzan, you Jane's knockers."

Stephen Sommers, director of The Mummy and Deep Rising, is apparently all but signed to direct a new Tarzan feature. But who will play the Lord of the Apes' swinging love interest? Probably not Sienna Miller, who made Sommers' admiration for heaving bosoms public during filming of G.I. Joe, which has just wrapped and will be in theatres next August.

Miller, who plays a villainess in the toy-based action-adventure, told journalists Sommers made her wear a fake chest for her role because he likes "girls with big boobs."

Miller admitted she was "mildly offended" -- which also happens to describe how audiences felt after enduring Sommers' 2004 flop Van Helsing.

Hollywood has been trying to get filmgoers excited about the Edgar Rice Burroughs-created character for years: From 1984's earnest Greystoke: The Legend of Tarzan, Lord of the Apes to 1998's laughable Tarzan and the Lost City with Casper Van Dien. Sadly for fans of the character, this film was almost directed by Guillermo del Toro, before he chose to make The Hobbit and an as-yet-untitled prequel to the Lord of the Rings trilogy.

A WANTED (SUPER)MAN: All indications are the next big-budget franchise to be rebooted is Superman.

Although 2006's Superman Returns cracked $200 million at the North American box office, that wasn't enough for Warners, which is expected to copy Marvel's approach to the Hulk following Ang Lee's 2003 flop: Namely, pretend the previous film never happened.

Although Bryan Singer is not expected to return and no new director is yet attached, comic-book scribe Mark Millar (who wrote the graphic novel Wanted was based on) is telling anyone who will listen (mostly online) that he wants to write the flick, with the intention of updating the character for the 21st century.

No word if this particular vision includes tattoos, curving bullets and Angelina Jolie.

Frankly, while we recognize all that was wrong with Superman Returns (Kate Bosworth's lame Lois Lane, the subplot about Superman having a kid, etc.) we miss the days when studios and producers would pull themselves up by the bootstraps after a crappy movie -- without throwing the super-baby out with the bath water (i.e.: The first Star Trek film clunked, so the franchise rebounded with Wrath of Khan without recasting William Shatner.)

And good luck locating a better Man of Steel than Brandon Routh, who admirably filled the big red boots of Christopher Reeve.