Has there been a successful shooter on XBLA / PSN yet? I am remembering Section 8 and... Battlefield 1948. And I think only the latter actually sold, right? Both have an "8" in the name.
Clearly, this game should have been called Batman Imperson8rs.
1943 did extremely well. EA left money on the table by not doing DLC for it. Monday Night Combat sold very well for an XBLA title and was a good game. Section 8: Prejudice is actually a darn good game with a lot of elements executed better than Star Hawk from what I've seen. Not sure how that one sold.
Those are the ones that spring to mind at least being of decent quality.
Stuff like Blacklight and Breach were shit.
Nexuiz comes out next money as part of the spring "House Party". Uses CryEngine and is an arena based shooter. I have a feeling that one will die hard.