Pockets full of devices? I can't see why. Two devices would be perfectly reasonable - one for things that demand connectivity (talk, text, net), and one for the other stuff (games, videos, music). Even if the 'other stuff' has occasional connectivity capabilities to download new music, etc.
When people say phones are for talking, it's not a frivolous argument - they need to be available for talking. Which has two implications:
1) What should happen when you have an incoming call? Do you lose your position in game, etc?
2) The battery needs to stand up to the demands.
As it is, 3G devices struggle to get through a day. It's not going to help matters by gaming on them for an hour or two - pushing the cpu, graphics, display to the limit. If your games console runs out of juice, it's generally less of an issue than if you suddenly can't make or receive calls.