The crew at Golem.de have posted a video off AMD's next-generation Leo platform powered by an unidentified Phenom II X6 processor, running on a Gigabyte GA-890GPA-UD3H motherboard based on the newly released 890GX chipset and coupled with ATI Radeon HD 5000-series graphics. There was no mention of specific clock speeds but it is said that the highest stock frequency of AMD's six-core chips will be 2.80GHz.
To compensate for the relatively low clock speeds and optimize resources, AMD's six-core processors will reportedly have some form of dynamic speed boost technology called "C-state performance boost." Much like Intel's Turbo Boost, C-state performance should kick in when single-thread performance is needed most, automatically disabling idle cores and overclocking the remaining engines to the maximum possible level.
Thuban processors are expected to be compatible with AM2+ and AM3 motherboards, presumably following a BIOS update. It remains to be seen whether the new dynamic speed boost technology will function on existing motherboards as well.