Ya, Bulldozer is not able to live againt the expectation, i.e. beating the 2600K. But I don't think it is a faliure at all. Just finished the legitreview and Toms Hardware review of the FX processor and find out that it is placed somewhere between 2600K and 2500K..in fact it is more closer to 2600K in terms of performance. Now after launch we can expect a price drop from AMD's side, making it a viable solution in highly multi-threaded environment and for multimedia applications.
And don't compare it with Sandybridge-E series processor, Zambezi was never meant to compete against Sandybridge-E. I think AMD has already provided their roadmap for 2012 and Trinity might be the true competitor for Sandybridge-E.