I can see this creating a huge market for the 'pure' Google Nexus devices, as they all come unlocked already. In fact, it was the deciding factor in my buying the Nexus S. No begging the carrier, and no money spent for a third party unlock.
Maybe when the cell providers start losing enough profit off their device sales, they'll see the folly of their ways. As it stands, I can see this creating a lot of 'criminals' in the interim by unlocking their hardware for travel.