Arkadian Warriors
Ex-MMO-addicts like myself will appreciate Arkadian Warriors, which seems to be a simple Diablo-esque action RPG where kindly old NPCs tell you to go to some dungeon and kill 15 whatevers. The demo only features one such quest (The whatevers? Boars.) but I imagine that the rest of the game is pretty similar. There are three character classes to add a little variety to the way in which you kill the 15 whatevers, but the demo only lets you hack away with the warrior class. This might be a fun title to revisit in those long, gameless summer months but I imagine you've got something better to spend your time on for now.
GripShift
A nice looking casual racer with arcade style loosey-goosey controls. Don't we have a few too many of these on the Live Arcade already?