AMD on Tuesday quietly announced that it would delay the roll-out of the company's next-generation flagship graphics product powered by two code-named Cayman chips. From the fourth quarter of this year, the new graphics board known as the Radeon HD 6990 or under code-name Antilles will be delayed to the first quarter of 2011 reports Xbitlabs.

At the financial analyst day AMD's graphics business unit quietly revealed a new roadmap for the short-term future. Based on the new roadmap, the company's highest-performance dual-chip Radeon HD 6990 "Antilles" will only be released in Q1 2011, which is a delay by several weeks from earlier unveiled roadmaps that were published on the Internet. In addition, AMD intends to release its code-named Turks and Caicos chips in the first quarter of next year.

The Radeon HD 6970 and 6950 based on code-named Cayman chip will be released this quarter, as planned.

At present specifications of ATI Radeon HD 6900-serires graphics processors as well as boards on their base are unknown, as a result it is impossible to make any predictions about speed levels in games offered by Cayman or Antilles products.

Considering the fact that Nvidia Corp. has just released its new flagship GeForce GTX 580, which offers up to 30% of performance increase over GeForce GTX 480 and generally offers a number of advantages compared to Radeon HD 5970, formally the highest-end consumer graphics card on the market, the delay of the Radeon HD 6990 is not a good news for AMD. The company's share on desktop discrete GPU market dropped from Q2 2010 to Q3 2010 slightly (from 44% to 41%, according to Mercury Research) after Nvidia released its GeForce GTX 460-series of graphics boards; the launch of a new flagship solution will impact sales of AMD's most lucrative high-end graphics boards and will also capture minds of high-performance graphics enthusiasts. The good news for the company is that its single-chip high-end offerings based on Cayman GPU are still on-track for the fourth quarter launch.
It should be noted that technically AMD can still announce the Radeon HD 6990 "Antilles" in 2010 in order to distract attention from Nvidia's new offering, however, even the company itself understands that the novelty will only be available in 2011 - Source xbitlabs

BTW we have not been able to verify this with AMD as of yet. We can however notce that the Cayman release is still on track as scheduled for a November release.