Phenoms work fine with the AM2 boards. Might need a BIOS update, but I'm pretty much already running a BIOS which supports Phenom. I won't be going Phenom though. They dissapointed me with it, I was hoping for a success.
Plus they are fairly expensive here. I'm just going to buy myself a new motherboard and get myself an Q9450 when it comes out and overclock it to 4GHz. Phenom will never be able to beat that.
How ever (offtopic) the HD4k series look very promising. nVidia might be in for a tough battle this year