OK, heres the scoop, Tom is working on Alien Hominid for all three consoles. Nothing has officially been said, maybe because O3 doesn't have microsofts OK to publish for xbox. BUT after looking at Gamespots On the spot show again, I noticed something in the TheBehemoth Studios... A green Xbox. It can mean 1 of 3 things.
A) its imported from Europe
B) its the Halo Limited edition Xbox
Most importantly
C) its the green Xbox Debug Unit.
(info about the Debug unit is here)
http://www.retrotime.com/html/xbox.html
The only reason I know about the debug unit is that when xbox came out, microsoft was having some sort of contest where you could win a modded green debug xbox that would play normal games.
So it looks like they are working on the xbox version, also (hopefully) its just not official if its going to get the green for xbox publishing.
http://www.gamespot.com/onthespot/