I wouldn't want to see a lot of updates. Much more than one a month I think I would find irritating, especially as more people join the site. A "hey, I am publishing this" notice is cool, perhaps something else for major accomplishments or news, but beyond that I wouldn't want to have a lot of "hey, I just added RSS for comments!" type of announcements.

One of the things about having a tab is that the launch announcements would stick around there a little bit longer.