There's also some stuff going around about mcp73 and mcp79 - both of these will apparently be DX10 IGPs, plus the usual improvements. Not coming out until late-2007/early-2008, though.
Then again, I'm not sure I'd even bother waiting if I needed to do a new build soon - if you find out you need DX10 later, I'm sure there will be some appropriately budget-priced DX10 cards available by that point.