When are the long awaited 8-core processors from AMD and Intel going to be commercially available? Will they use current sockets and chipsets or require new ones?

What kind of applications would fully make use of an 8-core 16-thread processor? Certainly there aren't any PC games that would need or use so much CPU resources. Do I really need this much CPU power if I'm just playing games, viewing photos, and browsing the internet?

I can't remember, but does the Ivy Bridge use Intel socket 2011 or 1155?