Strictly speaking a delay is not a correct word to use, as AMD have not announced any official release date, though this may not be a consolation to anyone waiting. According to Sweclockers, even though motherboard makers are ready to go with the 900 series- AM3+ chipsets it would appear AMD are struggling to make a Q2 release. Engineers do not have access to retail samples of the coming CPUs and only have 'scaled down' and 'locked' engineering samples. The situation is as such that some manufacturers may not even release their 900 series motherboards until release of the CPUs.
Release has been estimated to be around August or September, which is close to Intel's 2011 release, which could be business meltdown for AMD.
Sources say that a re-spin of silicon is needed and a delay may very well be real. Official announcement likely to come soon.
The currently available B0 and B1 stepping Zambezi/Bulldozer processors can function at around 2.50GHz/3.50GHz (nominal/turbo) clock-speeds and at such frequency they cannot deliver performance AMD considers competitive, a person with knowledge of the situation said on Monday. As a consequence, AMD needs to tune the design of the processor and create B2 stepping of the chip with better clock-speed potential amid similar thermal design power (TDP), which will take several months to complete. Therefore, the Sunnyvale, California-based chip designer will release its highly-anticipated Bulldozer processors for desktops in September, not in June, as planned.