Okay so i am a hardcore console player. Xbox 360 guy but every now and then i get on the computer for some Diablo III. So i guess it is a two part question. Where are the PC gamers? and Do you still play Diablo III?
If you are looking to play with some PC gamers, I would suggest you message KoG Fox XS. He is one of the Section Leaders over the PC area. There isn't a clan devoted to Diablo III, but he may know people that play it.
Also, feel free to hit up SHadowspy1 on the PC. He's in my clan, but he also sometimes plays Diablo III on the PC.