With Valve's history of security, after the full game is pushed through steam, I'm wondering how long it will take someone to figue out how to crack it and play without activation.
As far as which looks better D3 or HL2, there's more to a game than graphics. HL2 will look better because you can see farther than 5 ft. in front of you. D3's is all repetitive textures, close quarters, repetitive battles, and mindless gameplay. I've already had more fun watching the HL2 videos over and over than playing D3.
"You can either want something to be true, or you can want the truth. Pick one." - Mr. Diety