ACE Team, the independant developer responsible for Zeno Clash, has been discussing the probability of bringing their cult classic to the Xbox Live Arcade.
“We’ve been having conversations about a possible XBLA version of the game and we’re currently talking with a publisher, but we still haven’t closed that yet.” According to the co-founder, Carolos Bordeu
Because Zeno Clash was developed with Valve’s source-engine, there is a good chance that there would be a “little bit of extra content” if and when it is brought to the Xbox 360. If I were Microsoft Game Studios, I’d pick up on this one.
Source: Shacknews

I’ve been holding out on buying Zeno Clash, and this possibility will probably have me hanging on a little while longer.