At a press briefing this morning, Namco Bandai announced that the original SoulCalibur fighting game is coming to Xbox Live Arcade. We don't know but we strongly suspect its release will coincide with the release of SoulCalibur 4. They plan to have it available before July 29th, the day SoulCalibr 4 is released.
The re-vamped SoulCalibur will be HD and have leaderboards, but will only support local PVP.
PowerUp Forever is a space shooter, but with a ship that grows in size as it absorbs energy is also coming to the Xbox Live Arcade in the near future.