Ok, I just read that Sapphire is claiming their 780G supports 125W:
"Sapphire Technology is pleased to announce that the new high end, 125W Phenom CPU’s just released by AMD (Model numbers 9750 and 9850) are fully supported across the latest range of SAPPHIRE mainboards, including the high end PC-AM2RD790 - PURE CrossFireX 790FX, the new mainstream CrossFire board PC-AM2RX780 - PURE CrossFireX 770, and the microATX Hybrid CrossFire board with integrated graphics, PI-AM2RS780G - Hybrid CrossFire 780G.
The PI-AM2RS780G and PC-AM2RD790 will require a BIOS update to recognise the new CPU ID’s correctly. The new BIOS are already posted in the driver section of the SAPPHIRE web site www.sapphiretech.com
Of particular note is that SAPPHIRE has full support for these new CPU’s on its 780G product, PI-AM2RS780G. This is NOT the case for the majority of competing 780G designs as they have used a far less capable configuration for the power sections and will only be able to support the earlier 95W CPU’s. (9500, 9550, 9600, 9650)"
It is making me nervous about trying the 780G at all.
It has NOTHING to do with the 780G chip itself, the problems lies solely in the design of the motherboard.
Of the boards that we have retested the last two weeks, three now claim full support for the 125W TDP processors. These include the Gigabyte GA-MA78GM-S2H, Jetway PA78GT3-DG, and ASRock A780FullDisplayPort, all of which passed our test regimen. We have two other boards that do not implicitly state support for the Phenom 9850BE, but we found the Biostar TForce TA780G M2+ and Sapphire PI-AM2RS780G worked fine
As a recap, the critical aspect of running a 9850BE at stock speeds on current 780G products centers on the cooling of the PWM circuitry. Each and every manufacturer along with AMD agreed that cooling the MOSFETS properly was critical to the successful operation of the board at stock or overclocked speeds with the 9850BE - and to some degree, the 6400+ X2. This is based on the board manufacturer utilizing a properly developed power delivery system that is designed to handle the 125W TDP processors and in the future, the upcoming 140W TDP Phenoms.
As Anandtech discovered it came down to proper mosfet cooling.
It is recommended that you verify that whatever 780G motherboard you get should have a 4 phase or 5 phase circuit design and you have proper cooling over the mosfets.
I've got the GA-MA78G-DS3H (full ATX version of the GA-MA78GM-S2H) and it handles my X2 6000+ just fine. Not sure if the CPU is the 125W or 89W version however (haven't been able to find out how to distinguish the two).