Other than having six cores one of the most interesting features of the AMD Phenom II X6 processor series is a new technology that will be found on all AMD 'Thuban' based processors called Turbo CORE technology. For starters Turbo Core sounds like an answer to Intel's Turbo Boost technology that was introduced with the Nehalem processor series. AMD's Turbo CORE is automatically enabled by default and should work on all AMD AM3 capable motherboards after a BIOS update. The BIOS update is needed as obviously the settings for this technology were not available when Socket AM3 motherboards came out.
AMD's Turbo CORE is enabled on a six-core processor when three or more cores are not being heavily used. When Turbo CORE enables three of the processor cores get up to a 500MHz boost in performance, while the three at an idle state drop down to 800MHz. Turbo core mode doesn't disable Cool'n"Quiet, which means the cores can still throttle like normal. When Turbo CORE is enabled the increased voltage goes across all the cores, so no voltage gating is taking place on the remaining cores in an idle state. If you start using a multi-threaded application that calls for more than three physical processors then Turbo CORE disables and all six cores are run at the processors rated clock frequency.
AMD's Turbo CORE technology is a step in the right direction from what I can tell and should improve consumers computing experience by increasing performance when lightly using your system. The Turbo CORE technology is handled by the CPU and is all done automatically, so there is no extra work that needs to be done be the end user to use this feature on a daily basis.