We are connected 10 - 14 hours a day with the Gmail auto indicator in our tool bar which checks every 2 minutes and the times that it has been down are less than .005%. We love Gmail for our 3 businesses.
It seems to have expected outages for a beta project. Its not too bad and not 100% uptime.
Well, for a beta project that just came out, I'd agree, but they've been testing this thing for months. Personally, I've had problems with it not remembering that I selected the "Don't ask me for my password for 2 weeks" checkbox on the login page. But, I too have experienced some "oops, sorry. the system's not available right now. try again later." messages.
Hope this means they're getting the last few bugs out of the system and launch this puppy. :)