I dont mind double battles.
The type of double battles I would wet the bed over would be when someone joins you to get help (e.g. Eterna Forest / Victory Road thing / Riley in DPPt) because of all that excess exp and free healing you can be sure to use your strongest moves on any pokemon without fear of PP-exhaustion; and you get full EXP :3
But apart from that, I think we will see alot of double battles, and I would like to see some in Gyms as Gym Trainers or in the E4.
Something I'm hoping (that wont happen, oviously) is that we get someone to join our team before the first gym, but that wont happen XD