- can only resize a window from one corner, and that corner may be off the screen in certain cases so that you can't move the window to a position where the corner is even visible (this just bit me this week)
- still doesn't understand how to fullscreen programs (windows maximize function is the single best OS function I've seen that allows a user to focus on just ONE thing). I think this is fixed in the upcoming OS X but I don't have it.
- liters the screen, the doc, the global menu with all kinds of state icons to show running programs and background services, but doesn't have a built-in notification system so that the users have to install http://growl.info/
and more and more.
That said, it still manages to be a great OS. It was miles ahead of XP. About par with Vista.
But sadly, it's lagging behind Windows 7. And the new OS X versions just don't make me terribly excited. I'm ready for something new.