Much like the Radeon HD 4890 last generation, ATI is rumoured to be preparing a refresh for its Cypress GPU. Details are unavailable at this stage. Whether it will be a die shrink, increase in shader counts, or just clock speed optimizations (ala HD 4890) is unknown.

The HD 5800 refresh should come in right after the GF100 as a direct competition. If GF100 does end up competitively priced, ATI have a significant price cut buffer in the short term, with the refresh taking over within a couple of months.

Much like the Radeon HD 4890 last generation, ATI is rumoured to be
preparing a refresh for its Cypress GPU. Details are unavailable at
this stage. Whether it will be a die shrink, increase in shader counts,
or just clock speed optimizations (ala HD 4890) is unknown.

The
HD 5800 refresh should come in right after the GF100 as a direct
competition. If GF100 does end up competitively priced, ATI have a
significant price cut buffer in the short term, with the refresh taking
over within a couple of months.

Reference: Fudzilla