Groups upgrade on Google Apps

Apparently this isn't big enough news for the Google Apps blog, but the distribution list feature got an upgrade in early December and is now called "groups." There's a new member/owner distinction, and you can set up other list types than "Public."

I've wanted this functionality since I started using distribution lists in Google Apps, so I'm happy. The obvious question is how this product relates to Google Groups. Will they ever converge? Would I want them to? Google Groups is pretty heavy.