If you want to follow Mozilla's progress towards creating its own MSIs and supporting group policy, there's two pages you can follow:
The group policy feature, on the other hand, doesn't have much going on. It looks like FrontMotion is the best we're going to get for now.
Although this is technically a blog, it's primary content is a series of articles on how to get Firefox working in a corporate Windows environment. Later ones build on earlier ones, so you might want to use the Table of Contents on the right to read through it chronologically instead of reading straight down from here.