The original version, v1.X, was called K9A2 CF-F. The revised version is named K9A2 CF V2. The difference with the two boards is that the v1.X board has never had support for any CPU rated at over 95W TDP until maybe a week or two ago, while the V2 board had up to 125W CPU support from it's start. As best I can tell, everything else is identical. And yes, AM3 CPUs are compatible with AM2+ socketed motherboards, as well as some AM2 socketed motherboards. (It depends on BIOS update support.) Still, each motherboard's ability to support CPUs of greater TDP, or wattage, than the design was originally intended to support will vary. And that's the only question remaining - Will the v1.X board support a 125W CPU? Will it also support that CPU if it's overclocked/over-volted and happens to push the TDP beyond 140W?
When I called MSI, they told me it now supported 125W CPUs, but had no information regarding the overclocking of such CPUs.
Something else to take note of is there's a similar 790X motherboard from Gigabyte and it has the SB750 southbridge, whereas both MSI versions have the SB600. Gigabyte's board also has an 8-pin power connector, while our MSI boards have a 4-pin.