Well, my programmers are currently checking Unity out for a mobile port and so far
there are lots of good and bad which means a long climb from scratch to actual production as we work out what Unity provides, what we need, what we can get and how can we work around shortfalls...

Also trialling Skyline out, another competitor for Unity but miles away from releasing yet.

As always, its what you can drive that determines if you get there or not isn't it?