Simultaneous Co-op for Mario Galaxy 3 is pretty much confirmed? Or is this just another Wack-job with an idea...

[Kresnik]

I'd still be quite interested, even if it were Mario Galaxy 3. A new motif wouldn't go amiss, but there's still probably a lot of life left in the Galaxy design.

I'm not sure they'd go for it, though. New console is the best place to start afresh with something like this (i.e. Sunshine; Galaxy 1)