Earthworm Jim HD for the Xbox 360 and PlayStation 3 is a remake isn't it? The developer (Gameloft) is running a marketing campaign of sorts for it.
http://gamesas.com/forums/viewtopic.php?f=4&t=4358
Given the timing of the contest
I'd guess and say we're going to see a release soon, I think the summer could be a good guess for "Xbox Live's Summer of Arcade" promotion. The game is a timed exclusive for the Xbox 360 so I'd think it would be a good time to release it to take advantage of the month long exclusivity.
I didn't hear anything about an MDK remake or was it simply a wish list suggestion?
Edit: According to the Facebook contest entry for EWJ HD the "world premier" for the game is on May 28th, 2010. I don't think that is the release date since that's a Friday and Microsoft asides from the Ultimate Mortal Kombat 3 glitch never release an XBLA game on any day other than Wednesday.
http://www.facebook.com/event.php?eid=109436925762325&index=1