Our sources reckon AMD will be coming out with at least two high performance cards and one mid-range card by the end of 2009, with a possible fourth low-end card by the end of the year or beginning of 2010.
The single GPU RV870 card - which probably translates into the Radeon HD 5870 under AMD's current naming scheme - is expected to appear first, followed by a dual GPU RV800 (Radeon HD 5870X2) and mainstream RV840 GPU (Radeon HD 5850).
Back in December of last year we were told by AMD the 58xx series cards would be reserved for Q4 2009 to pair up with Microsoft's DirectX 11 launch, but with the advent of Win 7 rapidly approaching, that timeframe may have shifted forward a notch.
Nvidia had better hope and pray that TSMC can patch up its leaky 40nm bucket in time to catch up.