[ForALaugh]
...how 'bout... Barts in fact has all the roumored 1280SP but they decided not to use all as 1120 was enough to beat GTX460 and lower performance than 5870 so they could sell out the remaining stock and once GTX560 comes out we'll have a 6890 and Cayman has all the 1920 but.... apply the same theory as above with 5970 and GTX590 (690, whatever).
[/ForALaugh]