Utility of mages in Cataclysm

[Owltoid]

I'm currently leveling my shaman team (leveling priests to 80 doing only BG holidays on the weekend) but starting to question if I'd be better served by having at least one mage.

These may sound like dumb questions, but lots is changing with Cataclysm and I'm not sure about much:

1) Are mages still making water in the expansion? Is water cheap to buy or would it be good to have one to just fund my team with snacks, even if nothing else?

2) Dalaran pretty much made it so portals weren't neccessary, and the reduction in hearthstone will help - actually everything they're doing seems to be focused on minimize actual travel time. What are the experiences of the beta testers?

3) Anything else that I'm overlooking with mages?

I don't want to get a mage to 80 to just make water, as I'm sure that time spent leveling could have funded my vendor water for the rest of my WoW days.