I don't think it can be quite so clear cut.
Yes it is a pain that the phone is locked, but most (in fact all, I think) networks do allow you unlock it for a smallish fee at the end of the contract.
Also, I know of a lot of phones that are being used second hand that are still locked to their original network. This is due to friends and families all being on the same network and phones being handed down (/up/sideways).
So, no, I don't think it will be the death of second hand handsets, but it still is a pain, especially when some networks (ok, just one) make a complete hash of unlocking BB5 phones.
Man, I was nearly sitting on the fence there
