The ESRB is always a great place to spot upcoming Xbox Live Arcade titles with the word "arena" in the title (Wing Commander Arena, anyone?). Without the enormous lead times of their retail counterparts (see Shadowrun above), these digitally distributed darlings will often sneak in under the radar. Take the Xbox 360 listing for Quake III: Team Arena above. The 1999 multiplayer classic would be a perfect fit for the Xbox Live service (right alongside older brother DOOM), and the newly enlarged 150MB size limit could make it a possibility. Or maybe this is just a retail port, though we can't imagine it faring well in today's competitive FPS environment.
We've asked Microsoft and Pi Studios to comment on the listing.