According to Eric Meyer, it seems that there is hope that Internet Explorer 7 may have improved standards support. He’s got a list of “Top 10 CSS Fixes” that should be made. I would definitely like to add “proper support for PNG transparency” to the list. It’s not CSS-specific, but it is a browser bug that requires many site designs to implement IE-specific work-arounds.
And of course, there are many other bugs listed at the css-discuss wiki and Position is Everything that should be fixed: the “guillotine bug”, “peekaboo bug”, and the “creeping text bug” are ones that have bitten me on more than one occassion.