It was a previous job posting back in November last year that revealed that a Red Steel sequel was on the way, and another vacancy ad seems to suggest that the expected Red Steel 2 will support online functionality.
A new Ubisoft job post on Gamasutra advertises for an online programmer to "develop the online part of a game engine for a Wii project ... located in [Ubisoft's] Production Studio in Paris, where Red Steel and Ghost Recon Advanced Warfighter games have been developed".
With Nintendo flicking the 'on' switch on Wii's online multiplayer servers this Friday to coincide with the online-compatible Mario Strikers Charged Football, we'd fully expect the next Red Steel to pack an online multiplayer mode anyway. It would be a crime not to include one.
We're chasing Ubisoft and will let you know if we get anything juicy.