As soon as the rabid "It's still DRM" crowd either
a) Get's over their kneejerk reaction
b) Get's ignored since they don't buy games anyway
c) Get's distracted by the next Sony DRM debacle
people will realize that this is exactly what the industry needs. MMO's don't have (much) of a piracy problem, but game developers that want to just sell software need help. DRM has failed not because the concept is flawed, it's not, but because the implementations have been silly. The idea that you can create a procedure and have it work without change forever is simply a waste of money. I can already think of several methods of lying to this kind of system, but Steam makes things harder just by combining a form of file check along with a log on to a remote server. To "lie" you will have to convince Steam that are a registered user, have permission to run the game you want to pirate, and your file(s) matches the CRC or other check they do. Once someone figures that out, or even _gasp_ before, they can add another check (or set of checks) to make things more difficult.
Many imperfect walls > 1 (supposedly) perfect one
The one day you'd sell your soul for something, souls are a glut.