No one knows when the new cards will launch. If you read this thread you will see that it could launch as early as next Monday, but if so AMD has done an amazing job at keeping it very quiet, because as of right now we know next to nothing about these cards.
On the other hand some people are speculating that they might not come out until as late as May of next year.
At this point your guess is about as good as anyone's. Personally, I would wait until at least next Monday, since that is only 6 days.
After that, I don't know. My new 2500k system is currently being gimped by a 8800GT because I decided to wait. But since I'm mostly playing The Binding of Issac and Path of Exile (neither is graphic intensive) I'm willing to wait for a bit more. If I get Skyrim for Christmas I might not be so patient.