You can't move North Bay because of the "Hole", Trenton is one of the biggest Air Force bases in the CF, and the last time I was in Trenton, I didn't see a whole lot of room to be able to move Kingston there. Moving Trenton is out of the question, the amount of land required for a military airfield is pretty hard to come by.
I agree with pbi and bossi, we cut a huge amount of bases in the 90's in favour of the mega bases. We closed Calgary, London, Summerside, Cornwallis, Chilliwack, 2 of the 3 Military colleges, Portage la Prairie, we also just recently moved 2VP out of Winnipeg, I'm sure there's some I missed but you get the idea. During the whole Sept 11th ordeal, it was found that 2 fighter bases wasn't enough, so after moving all the fighters (I include T33s in this) to Cold Lake and Bagotville, we now had to send out detachments of a few fighters to Comox, Greenwood, and Trenton to be able to respond quick enough to emergencies at the major centres.
I don't think closing more bases will accomplish much, that's just my opinion though.
Cheers