Mr. Brumby, the MSI card's copper heatsink uses a thin layer of silver thermal paste for the GPU core; the memory gets really, really thick white thermal pads that, as far as I can tell, carry maybe 5-10% of the memory's heat to the sink.
The AGP bridge sink is a separate little passive piece; I was able to retain it when I installed the VM-101 to my card. I have not yet checked its temps, but I never really felt that a little chip converting signals from PCI-Ex to AGP and from AGP to PCI-Ex could get that
if you're going over the card's texture memory limit and have to fall back on the AGP aperture, that may happen, but few games currently do that. Perhaps it could become an issue later on...
j-azn, the card does not show up under nVIDIA's standard temperature panel (Actually, the panel itself never shows. Ever.). MSi also includes a very wonky Macromedia Flash 5-based program that seems like a relic from their GF4 series of cards that's supposed to report all sorts of stuff like the GPU temp, speed and voltage, but despite my deepest efforts for several nights in a row, I can't get it to work with the card. First few nights I spent just getting the software to not crash (involved doing some crazy stuff to my Flash plugin) and then when it worked, it received pretty much nothing from the video card, and despite my fudging with drivers of all sorts (finally fell back to trying two different MSi-released versions of the ForceWare), the stupid software just wouldn't listen to my card.
I haven't yet tried SpeedFan; I know that SpeedFan works with my XFX 6800GT in the gaming rig, but haven't yet tested it on my MSi 6600GT.
I'm not 100% sure the AGP 6600GTs can read from the on-die diode. Anyone can feel free to correct me if I'm wrong on that (I've seen reports of PCI-Ex 6600GT cards reporting temp just fine in the ForceWare temp. panel).
EDIT: It's really hard to type without erring when at the airport, on WiFi, with AIM Quick Buddy open and AcAuRoRa IMing you...