Stephen Wildstrom over at Businessweek has news for Microsoft Vista hangers-on: it's not worth the wait.
Expectations for Vista SP1 may be unreasonably high because Windows XP had such a successful overhaul in a 2003 upgrade called XP Service Pack 2. In contrast, Vista SP1 is mostly a bundle of bug fixes and performance upgrades, many of which had been released previously. There's a lot of improvement under the hood in the form of better stability, security, and compatibility, but very little of it is in a form users will notice.
It's just a new product, and one that isn't nearly as innovative and intuitive as Microsoft may have hoped. But then, neither is Leopard, Apple's new operating system.
It seems to me that we've reached the end of the road of desktop innovation qua desktop innovation. Desktop innovation in the future will likely happen in the cloud (i.e., web-based applications/services).
In the meantime, if you have Vista Microsoft has an update for you. It won't be anything to write home about. But then, neither was the original product.