Thanks for the feedback so far - we're definitely listening! Part of the purpose of this blog is to have the good two-way discussions as well as getting these sometimes tough messages out there.
@Ian - glad this has helped your planning. The best advice I can give is to check with your vendor(s). The APIs that they are using probably have not changed (we definitely apply different criteria for an internal API vs. an API we expose to others), but only they would know if their product has been tested and is supported on the new version. At the least, they may have an update you should apply.
@Julian - You'll want to check the (new) supportability matrix which should help with this question:
http://technet.microsoft.com/en-us/library/ee338574.aspx
Microsoft
