Probably looking at 9xxx parts if you're looking for an actual upgrade over 7xxx. AMD recently announced 8xxx would be "OEM-only" rebrands, but I suspect they will trickle down into the retail market as well and replace the current 7xxx line-up.
http://www.anandtech.com/show/6570/amds-annual-gpu...
I doubt we will see Sea Islands in the next quarter or so, if Sea Island launch was imminent I think AMD could've convinced their OEM partners to hold off.
We will probably know more in a month or two as rumor has it Nvidia is gearing up to launch their Kepler refresh headlined by the long-awaited BigK (GK110). If AMD isn't ready to counter with actual product, I'm sure we'll start seeing leaked specs instead.
Well assuming their 8xxx parts replace the 7xxx parts in the price structure instead of being added in above. I am not going to get price gouged like all those poor fools who bought a 7970 when it was first released.