Considering Vista is still in beta, I would expect some things to be ironed out.
From my perspective, Microsoft has a number of hurdles to overcome. The first one being that for a lot of people, investing in Vista will also mean investing in new machines that will be capable of running it. I expect that will cause some grinding of teeth on company boards (yet another cost) that they could probabaly well do without.
That is where Linux should have the advantage, but then the disadvantage is one concerning the need for education of the workforce in respect of how to use Linux.
Likewise, that is also the problem for Mac OS-X.
Both are very powerful alternatives, but in the end Vista will inherit world OS dominance simply by dint of Microsofts' market share...
Also, Microsoft, should also stop pretending that Vista is a whizbang revolutionary leap forward. Compared to Linux and OS X offerings, it is more about trying to keep up, rather than setting the pace.
Perhaps only Redmonts' PR team and a few die~hard MS fanboys will say they'll "love" Vista, but the fact of the matter is that for most, it will be simply like an eight tonne Elephant ...big, loud and in need of a hell of a lot of feeding...