They are important without a doubt. But their importance is also often overrated and sometimes used by the competition as though there would be a lack of strategy. In some cases roadmaps are used to show a product(line) does have a future. “See we don’t have a issue with our software strategy because our roadmap extends well into the future”. My view is that a few simple slides do not capture everything, but I have to say sometimes they do make life easier. Unfortunatly I don’t have a simple answer to the Microsoft Product Roadmap. There are simply too many products and different strategies that go with it.
Although not a simple slide with dates, in my view Architecture Strategy Series : Technology Roadmap gives a good insight as to what Microsoft is up to in the Enterprise space.
Good and more detailled information is available to customers and partners, but only under NDA
An external source providing a complete overview of the Enterprise Product Roadmap is Directions on Microsoft : Directions on Microsoft – Enterprise Product Roadmap; unfortunatly this is not free information.
I promise to dig into this a bit deeper; stay tuned.