IMO,the conservative estimate AMD publicly gave comes from the current 32nm node condition @ GloFo(lower clock speeds than projected on the first batch of ES?).I think GloFo will certainly clear the issues by the time mass production starts next year,but for now AMD must use what they have.Remember ,this is all around new chip design with 8 monolithic cores (x 2 in server parts,via direct connect MCM) and they(AMD) must work within previously set power bands. As the node issues are cleared up AMD can better project the end clock speeds and thus the performance.