What is the schedule for the fee escalation? My understanding is that blocks are currently awarded for confirming transactions on the block chain. Once all the blocks are released, the fee would have to be pretty high (comparable to the cost of btc blocks) to keep people confirming the transactions...
I actually think the fees will slowly replace block rewards slowly and without too much planning and will just happen organically. As Bitcoin grows, so will total fees. Perhaps the block reward with fees included may never go under 15 BTC. (Who knows what the minimum will be though..) The free market at work!