Maturity is reached
I feel that desktop operating system maturity is reached. Think of all the new features that Steve Jobs announced today for Leopard. None of them is to “die for” (even for the impressive Time Machine, most users don’t care about backups).
This is not to say that all the new features of Vista and OSX are not welcome. On the contrary. But I don’t see most of these features being as important to the usability of a desktop as features arriving with Win95 (even if the OS was unstable) or OSX 10.3. Instead, most are nothing but “brush ups”, clean ups, refinements, beautifications, and in some cases, useless eye candy and pure cpu suckers. I feel that for the current computing model, keyboard-mouse-monitor, OSes are pretty close to the best they can be in terms of desktop experience. Which is good, as it will be easier for less fortunate OSes to catchup on desktop experience, e.g. Linux distros.
Maybe the next big company in technology, in 10 years from now, instead of showing off their brand new shiny animated UI, they will show us a completely new way of using a computer.