In the most recent issue of BrickJournal (17) there's an interview with designer and far-out space nut, Mark Stafford, about the development of Alien Conquest. When asked point blank if we'd see any more Alien Conquest in 2012, he was unsurprisingly evasive and couldn't comment on anything, but teased a bit that space is considered a LEGO "evergreen" theme. There was a photo next to this quote with with some ADU prototype minifigs and some red figs with the new space helmet
and what looked like a variation on the Classic Space logo on their torso. I wish I had the picture to share, but I don't. If I get a chance I'll try and scan it.
I don't want to get anyone's hopes up, but Mark didn't out and out say there would be no more Alien Conquest this year and if I'm not reading too much into things, there might be something just as cool in the works.
In any case, the interview is an interesting read if you subscribe or can otherwise get your hands on a copy of Brick Journal 17. Apparently, Alien Conquest was something of a wildcard late-comer when LEGO began planning its next space theme. Even in its unpolished state, the Alien Conquest concept tested well with the kiddies. So well, in fact, that in spite of going up against 4 other concepts that were in a more advanced state of refinement, Alien Conquest went on to become the next space theme. It also seems that certain collectible minifigures and parts may have started life as Alien Conquest concepts. Namely:
• the ray gun
that came with the Series 1 space dude is the alien weapon of choice
• the Hazmat guy from Wave 4
seems to have originally appeared in Alien Conquest concept sketches
• the stereotypical "visitor" alien
that was originally proposed for Alien Conquest (and eventually scrapped) made it into Wave 6
• the dark blue space marine
from Wave 7 may be an evolution of some early ADU figure ideas