I highly doubt Shinji Mikami has anything to do with Resident Evil 5. After the failure that was PN03 (sales-wise), he stepped down from his manager position at Production Studio 4, and was replaced by Noritaka Funamizu in 2003. Then, after the release of Resident Evil 5 in Japan, he left Production Studio 4 at the end of 2004 and started working at Clover Studio, possibly on an unannounced title for the next-generation. I do believe Capcom Production Studio 4 is working on Resident Evil 5, not Clover Studio.
Clover Studio was founded by Capcom in Summer 2004 and now houses talents such as Atsushi Inaba (Viewtiful Joe, Tekki, Okami, Under The Skin,..), Shinji Mikami, Ryuta Takahashi (Resident Evil), Shinji Utsunomiya (Devil May Cry), Haruhiro Tsujimoto, Tamio Oda en Yoshifumi Yamashita (from the Flagship studio, made The Legend of Zelda's for GB and GBA).
Resident Evil 5 is a nice move for Microsoft and Sony, but there really is no need bashing Nintendo for that like they do on other boards. They have not yet started showing titles, so Revolution could as well get the title. They are launching last after all... It won't help Microsoft in Japan though, they need much more.
On the other hand, there could as well be a huge surprise in store for Nintendo, coming from Clover Studio.