AMD made a big launch today, introducing after much delay and much trouble in the market their first 45nm Shanghai processors. The CPUs, currently only offered as Opterons, are intended to be used in workstations and servers, an arena where AMD still has at least some sway.
The desktop variant of the CPU, Deneb, is not yet here - and there's no set date as to when it will be. AMD's recent failures with Barcelona and Phenom have cost them significant marketshare and have lead people to not expect much. Their new 45nm CPUs have a higher clock frequency cap, with Shanghai reaching at least 2.7GHz. Whether that coupled with the additional L3 cache added to the CPUs will be enough to sway hearts away from the Xeon remains to be seen.