It's a chicken-and-egg thing. Sites won't go IPv6 until ISPs provide the right infrastructure, and ISPs won't provide the right infrastructure until forced to because some sites are IPv6 only.
I think you'll see a lot more action on this in the next two years now that the main pool of IPv4 address is exhausted.
Truly, today, though, essentially nothing on the net publicly is IPv6. I actually hooked up with Hurricane Electric's free tunnel and had IPv6 working at my house for a short time (yes, through my Time Capsule -- worked fine), and I had lots of trouble finding anything to surf. Yes, Google and a few other sites have IPv6 sites, but they really are essentially no different than IPv4, or else they are specific sites just meant to test IPv6 (no real content). So, at least as of today, you're not missing anything.
Very few US ISPs have IPv6. Most are just in the beginning of tests with a few select customers. This is going to change over the next few years.
It isn't as simple as just flipping a switch, because as I mentioned, every computer becomes a fully addressable node on IPv6, and DHCP goes away, to be replaced mostly with a protocol where your ISP gives you a prefix, and your equipment appends a long suffix. Those two together uniquely identify your computer and can be found from ANYWHERE on internet. That means the routing protocols have to track a phenomenally larger number of routes than they did before, or (in practice) they have to hand off the job to routers down the line. The whole addressing scheme works differently and it will take some time for the ISP equipment to be fully compliant.