This topic comes up after every release or demo of a new version of OS X. We are getting 10.5 in 2007. It will be interesting to see if Apple keeps giving us dot releases every 18 months or if they make a big jump to OS 11.
If the 18 months holds up we could be getting 10.9 in 2011. I could just see Apple jumping right then (for marketing) and releasing OS 11 in 2011.
While UI eye candy is nice, the major feature I'm waiting for is grid computing throughout the OS and throughout every app. As Sun Microsystems said, "The Network *is* the computer".
I'd love to be using all the CPU power in my house when encoding HD-DVD or H.264 or whatever the next big thing is. If my son is just surfing or chatting with his duo core iMac let me grab some of his CPU and use it to speed up my more intensive tasks.