According to AMD's latest plans, you can expect a new IGP chipset with AM3 support in very early Q3 2009. The new chipset is codenamed RS880 and it will be matched with SB710 Southbridge.
This chipset should replace AMD 780G with SB700 chipset while AMD 790GX will get a replacement at some point in Q4, called RS880D. The new chipset will feature improved performance of its DirectX 10.1 integrated graphics, additional power saving and enhanced Avivo HD technology.
The SB710 comes with 6 SATA 3Gb/sec ports, Raid 0,1 and 10, advanced clock calibration and 12+2 USB ports. We can only hope that this chipset and the machines based on it will be ready for back to school period, and this will only work if the company can stick to its schedule.