I think their next major attempt will be with Natal. They've had top Japanese game designers talking about it from Capcom, Konami, Tecmo, FromSoftware, Sega, Namco Bandai, etc, and I would be very surprised if there hasn't been any backroom deals made.
It will be interesting to see what exclusives will be available there at launch, especially ones that cater more to Japanese audiences and from Japanese developers.
We also haven't seen what Itagaki is up to or the big game that Mistwalker has been working on for the past 2 years.