Semper Fi: If that happened to me, I don't know what I'd do.
One of the reasons I've always been afraid of buying a large tank is because of just that - I also think of what it would have been like if it was a 50 gallon instead of a 10 that doused my living room.
My guinea pigs are really the heroes. They were squeaking at the dripping/pouring noise for about 30 minutes and I finally said at 2:30am before I was going to go to sleep, "Let me go say goodnight to them and give them a treat so they'll shut up."
All the fish would have certainly been dead - and the livingroom destroyed - and a day at work lost to cleanup - if not for them (considering that I usually just go straight to bed.)
Update:
I transferred the water and fish into the new tank. Surprisingly, the levels were fine when I got home since I saved the tank water and gravel (w/ the beneficial bacteria). I double filtered the tank for about five hours and saw a significant change in the cloudyness as everythng settled.
Before bed I place the fish in and wished them luck since I knew they'd die in a filterless basin and I had no other choice but to either a) put them in the tank, b) keep them in the basin - I have no way to get them to a LFS that would cooperate since the closest one is PetSmart (and I highly doubt that they would accomodate me in the slightest.)
This morning the tank looked much better, the fish were active and all went for their food. Casulaties: One zebra danio, and one bumblebee gobie.