How are you getting on with that? I do similar stuff, and love the idea of just docking in a tablet rather than a full laptop. I assume battery drops pretty quickly while running VMs?
I do love however that my laptop bag has gone from weight a tonne to something I can lift with my little finger. The bonus is the wacom pen, touch input and well, it having the potential of a tablet.
Edit: You can get quite a few hours out of it battery wise. But I generally have it plugged in when I'm doing real development work.