Though the HD 5000 series has been selling very well, but ATI isn't about to take a nap any time soon. In a conference call on fiscal earnings, AMD CEO Dirk Meyer mentioned plans for an upcoming product line refresh: "We are ramping the ATI Radeon HD 5000 series now and look forward to refreshing the entire lineup in the second half of next year," he has been quoted as saying.
The "next year" is refering to the company's fiscal calender. So that means that the actual date for release will be the second half of this year. AMD is planning the move to 28 nm, so perhaps the existing Evergreen line up (Radeon HD 56xx, HD 57xx, HD 58xx, etc) will get a die-shrink and perhaps a clock boost.
We'll have to see what new products come out, but one product that will almost certainly be due is a HD 5890 video card. Many expect that this will arrive when Nvidia brings their overdue new Fermi design to market. The high-end Fermi powered Nvidia GPU is rumored to be about 25% faster than the HD 5870, so we would guess that a HD 5890 will offer about the same amount of performance as GTX 380 (unconfirmed name). But of course, will have to get the hardware in our testing labs before we make any conclusions.