RSS/Atom would be ideal for me in particular, but I'm not sure if this would be the majority's preference. An email would be just fine. Both would be superb.

This is a bit of an issue I have with GC as a whole. Some products don't even have release notes. And I have to check a bunch of different release notes pages for each service, unless something gets announced on the blog.

I really want to stay on top of this stuff, but it's pretty difficult to right now.