I think retro went throught a little bit of difficulty, or should I say 'restructuring' after the release of metriod prime 3. I think a few of the senior members of the development team left shortly after the release to found a new studio with EA. Can't remember where I read it but I remember reading about how the former retro studio members were excited about working on the HD consoles, and wanting to make 'high risk' games. I think the loss of those members slowed down any subsequent projects, hence why nothing has been shown so far.
Of course, this may not be true - I'm just putting 2 and 2 together.







