Mmm, I'm not sure if I'd like a spinn-off. I think it's better to let fan fiction writers take care of that. (there is decent fan fiction out there, you just have to squint a little). I'm all for a non-human crew though, especially a race like the andorians. Vulcans, Klingons and Romulans got a little boring imho.
Something I would really like to happen is a new series taking place at the academy. There's so little known about that part of the star trek universe.