When checking for updates, the addon item will show "Checking for updates...". However, if no update is found, this notice does not disappear. Additionally, there is no notice that no update was found.
Landed on trunk as a part of bug 554007
Verified with builds on all platforms like Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.3a5pre) Gecko/20100511 Minefield/3.7a5pre ID:20100511030640
Blair, can't this really be done in an automated test?
Covered by the Litmus test: https://litmus.mozilla.org/show_test.cgi?id=15175