a server renting company which challenges the very popular Planet, officialy claims that it expects Barcelona 2000 series AMD quad cores in Q1 2008.
The company plans to offer AMD Opteron 2258 - 4 x 1.90GHz - 1000MHz FSB, AMD Opteron 2260 - 4 x 2.00GHz - 1000MHz FSB, AMD Opteron 2262 - 4 x 2.10GHz - 1000MHz FSB, AMD Opteron 2264 - 4 x 2.20GHz - 1000MHz FSB, AMD Opteron 2266 - 4 x 2.30GHz - 1000MHz FSB and finally AMD Opteron 2268 - 4 x 2.40GHz - 1000MHz FSB in Q1 2008.
Currently, you cannot rent a server that has a Barcelona-based Opteron inside. The company also claims that you should be able to make a transition from an existing dual core Opteron machine to a quad core. This is why Softlayer only uses 1000MHz FSB CPUs and these are limited to Hyper Transport 1.
There was no mentioni of 2.6GHz or faster parts.
You can check the informations here