Almost 2 months ago I briefly noted there is a new MSDN ESP Dev Center.
1) the entire ESP SDK doc-set,
3) new downloadable samples as well as samples that were in the FSX SDK,
4) a supported developer forum at http://forums.msdn.microsoft.com/en-US/ESP/threads/,
5) links to the ESP blog and more
The forums have at least 1 developer ( Tim, aka Beatle ) and 1 partner manager ( Todd ) so both technical and relational/marketing/business questions are covered. There are at least 3 pages of threads already and I see a high percentage are getting fully answered. So if you are working with ESP or just kicking the tires, this is definitely a place to know about.