I did. They told me: "The E7 blog posts on the topic represent our response. We will not comment further".
Move along. These are not the droids you're looking for.
Phone them and say something like - "There is still a great deal of confusion in the community at large. People want to know if Microsoft is committed to improving UAC in the future, and how taking pressure off ISVs impact that effort?"
"Will UAC ever offer a genuine admin / user split for processes? Will Microsoft change all processes to start with, similar to a low integrity level and thus blocking cross-process interactions unless escalated to a privileged account?"
Then ask them to add an easter egg into the next version of Windows