We have just published our review of the Abit AX78. This is their budget AM2+ motherboard, which does fully support Phenom processors and Crossfire X. For just around $90, it performs pretty well, and overclocks.. well, read for yourself ;)
The major issue with the AX78 is that it uses what is essentially a flawed Southbridge chipset to begin with. The years-old ATI SB600 has always had problems with USB and SATA performance, and AHCI is essentially broken. Once you get past that though, it’s a pretty good effort by Universal Abit.