Last Cameron rumor I'd heard was that he'd just begun pre-production on a mega-budget scifi adventure. No story details were included, but my first thought was that he might make a "first Mars mission" pic, given his interests. Prior to that, the rumor was that he was going to make Alien 5, and the scuttlebut at the time was that he'd contacted Schwarzeneggar about starring. I'm not sure Arnie has the time anymore, though.

I read an article years ago about the making of Aliens in an excellent mag called Cinefex. The FX technicians on that film were in awe of Cameron, who started his film career in special fx. Again and again, he'd push them beyond the limit of what they thought was possible, but he had the hands-on experience to jump in and help them get it done. The guy shoulda been an engineer, maybe.