Yes right the Diablo servers were down in 1 hour. And everything Blizzards said was they didn't expect such a huge amount of people.
But they are trying to fix the server issues today. But they didn't want to say an exact time for prevention of the servers. On a few a other blogs and youtube there are a few people talking about the error 37. For those who still don't know what this error means Error 37 means that the server are down.
And for those who can finally play Diablo 3 have fun.