FSX SP2 is now available for download here:
http://blogs.msdn.com/ptaylor/archive/2007/12/14/fsx-sp2-is-available-for-download.aspx
This download is for those that have not installed Acceleration, which includes SP2. This is a 166 Mb download, so you will need a high speed connection.
You can read about the fixes/improvements made in SP2 here:
http://blogs.msdn.com/ptaylor/archive/2007/10/02/acceleration-and-sp2.aspx
Bob S.
Senior Command Captain
E.V.P. Scenery