Interestingly enough, that's exactly what Microsoft announced at E3 last weekend. Their new console, the XBox One, will essentially run off of licenses rather than discs. The game disc is nothing more than a delivery mechanism, which means that unless you register a game you dont have it. They prety much said that they would allow publishers the option of allowing used game sales (or not) at their leisure.
It's essentially steam, but minus the great sales and nigh universal selection.
On the general front, the difference between used game sales and regular piracy is scale. If you buy a used game, that's one lost sale. If you put a game up on bittorrent, thats an untold amount of piracy. That's why the Napster case became so famous despite the fact that downloading was around before Napster.
Ha, That Blizzard. They aren't shy to leverage their great reputation in order to fix prices on their games for life. Now if only they wouldnt pretend that Warcraft 1 and 2 didnt exist.
Man, this thread is seriously putting me in the mood to go back and play some Warcraft 3.