Second, I think there's an implication here that prior releases of OS X have been great. They have not been great. Snow Leopard was solid, because that was its only goal. Much of what Apple has attempted with each release of OS X has been unsuccessful; remember when people were upset by Spotlight's mdimport grinding machines to a halt, or Filevault messing up home directories?
The reason these things don't stick in our head like Vista is that Mac OS X is a lot less important to Apple than Windows is to Microsoft. And Vista wasn't that bad! We just obsessed on the market's poor reaction to it. The market for the most part doesn't care about OS X.
I also like "OS X Kitten" as the next OS name. That, or they should switch to Pokemon.