Ok, it hasn't really been a year - the Vista launch was "officially" January 30, for consumers, with the actual release tepidly launching 60 days earliers to businesses and developers on November 30.
But its interesting to note the contrast betwixt Vista's reception and Halo 3 (which just launched September 25).
I don't think there's anything wrong, per se, with Vista (other than the ridiculously massive gap between it and the last major OS release from Microsoft) - and there's much to recommend - but, it reaffirms for me that OS'es increasingly won't matter. Note that although Vista projections are down from MS, XP projections are up - the message seemingly that one's just as good as the other.
I don't mean that snidely - as computing has moved from novelty to utility, consumer interest will be be driven by experience, not capability. That is, "What have you done for me lately?", not "What could you do for me lately?" - which explains Halo's, um, halo.
Natural enough, but it probably has some significant implications in how Microsoft will/should think about the future of its platform... generating infrastructure that creates platform lock-in will be increasingly difficult.