These days, this game is not the only Wing Commander game with multiplayer support. There's Wing Commander Prophecy for the GBA, featuring multiplayer support (by linking four GBAs together with a cable). The game is developed by Raylight Studios, not by Origin, though.
Armada is the first Wing Commander in a real 3D environment. Up to now you were fighting sprites, now you can fight 3D models.
Wing Commander: Armada is the only game to date in the Wing Commander series to feature multi-player support.