I wouldn't want the developers to stick with an API that is 7 years old. I think many of us, after 7 years of changes, expected to see significant differences on our computer screens looking at game X running DX9 versus game X running DX11 on the same PC. That's what people are having a hard time with and that is why people still have Windows XP running DX9.
These slight performance improvements and other minor improvements after 7 or 8 years of development are quite sad actually, even if it does provide developer improvements (which of course are crushed by the developer incentive to support the more lucrative console market, which happens to be DX9).
This comment was edited on Jul 6, 2009, 18:00.