Getting a lot of reports of people having trouble with their Gmail accounts. In the Gmail Help Discussion Group, I've easily seen several hundred users who say they are getting blank white screens, that they can only get in by trying a different browser, that they have to reboot their computer and wait fifteen minutes, dissapeaing label colors, dissapearing menus, dissapearing chat box, unending "Loading" messages, getting the older version of Gmail, and other problems. The "Issues logging in" board has 140 posts since this morning, 154 yesterday, and 54 the day before.
For now, your best advice comes from a poster (non-Google employee) called LMckin:
try the alt url https://mail.google.com/mail/s/
or the old version https://mail.google.com/mail/?ui=1
Whatever the problem is, the solution seems to be to clear your cache, switch browsers, or try those alternate versions of Gmail, at least until Google figures out what the hell went wrong and fixes it. If you're having a problem, fell free to leave a comment.
Thanks to Arie for sending this in.