What if the Dashboard -> Site Admin page was a Dashboard like how the Dashboard functions for endusers?
Along the left would be a feed from the mu blog (oh wait. there isn't one. OK, how about the wpmu category from donncha's blog?) and a listing of the last updated blogs on the site and along the right would be a feed for trac checkins as well as trac tickets?
That way it would also be easier for admins to keep track on what's being upgraded and what errors and bugs are being ticketed. And, since Donncha makes a changeset for each new version, you would find out that there's a new version. That's been mentioned from time to time around here.