Hot on the heels of the AM2 & chipset hub-bub today are the Angry Crustaceans with their list of all of the heatsinks you'll be able to use on your shiny new mobo. There really aren't many that are straight-up compatible, but it looks like the Shrimpies are hopeful with the possible introduction of some custom brackets...

"A new AMD socket has been launched, and with it a new mounting bracket, it renders a lot of well known heatsinks useless, we've compiled an extensive list of those which still fit the new AM2 platform out of the box."