Google Apps for Education works the same way as Google Apps Premier, with a tad less online storage space per user. The wonderful things about it is that any user can limit any publication to just those who are on the domain, if they wish. We use this when we are publishing something for only district staff. In addition, users can always selectively choose outside users (like our students on the other domain) to see their Docs, Calendars, Sites, etc.
When you administer Google Apps for Education, you can chose to allow access (or dis-allow access) to the suite of tools — Email, Calendar, Docs, Talk, Sites, Video, and Web Pages — for all users. Google Groups and Blogger are not in the suite, but, of course may be easily used.
The use of these Google Apps has moved technology ahead rapidly in our district. Between shared calendars for school-based meetings to internal Google Sites acting as mini-Moodle packages, both teachers and students have made good use of the apps for communication, collaboration, and creation.