Yep. It's me, leaping on Apple's choice of GPU again.
But aren't consumers going to be a bit miffed when they find that the new 20" entry level iMac has overall lower graphics performance (the 2400 series only has a 64-bit memory interface, which considerably hampers performance) versus the lower-spec old 20" iMac (which has an X1600 with a less-hampered, though still rubbish, 128-bit memory interface)? Especially when OpenGL standards haven't yet been updated to take advantage of the DX10-class features of the new chip, so other advantages like geometry shading which are available on the Radeon HD 2xxx series but not the old X1600 are moot for OS X...?
And what about the entry level 17" model which was a direct replacement for the eMac? What are education buyers who don't need the fancy GPU and extra cost going to buy? Dells?