I never thought I'd see the day Google would fail, but apparently, they can and they do :P.
They apparently had a similar outage back in August 2008, although I didn't experience it back then (I only discovered it as I frantically Googled this morning trying to find out what was wrong).

Still, gmail has been good to me and I actually slept through most of the outage, so if all they've done is left me emailess for 45 minutes, I can forgive them.