While this is nothing but a rumour for the time being, this story recently posted at The Inq indicates that both Terratec and Creative would no longer offer ATI graphics cards, at least not for now and probably not for this generation of hardware.

We don't know what broke up the marriage, but it's obvious that Creative Labs is unhappy with the current arrangement.
Creative will continue to support its current customers that have already bought cards and will supply product for as long as it necessary.