There is no way to confirm or deny. This rumor is based on the XFire numbers dropping, however Blizzard is never going to release this information, and there is no way to probe server traffic like an MMO (like: SWOTOR)
As for the game, Blizzard had a **** design. They expected palyers to spend weeks in Act I inferno, slowly grinding gear, as they fixed issues and added content. In essence, the RMAH was not supposed to even come out after Inferno had been even half-way cracked.
However, because they refused to do anything but internal testing, players found bugs and explots quickly, and beat inferno/began farmin Act III-IV. Following this, gold AH market was flooded with much better gear, allowing even more players to get into late inferno. It crashed the economy. Players solved the game months ahead of where Blizzard wanted you too. So now there is not any more content for players to work towards.
This is all because of their arrogance and unwillingness to extend a beta test to anything but the first half of Act I normal. If players were allowed to test lvl 60 characters most of this **** would have been caught and fixed. It's their own fault, and the designers inability to understand what Diablo II offered in the end-game.
Side note:
That Wizard invincible bug? That was found two months ago. It's only being looked into now because some idiot blabbed about it on the forums. Keep in mind, there are lots of eploits being used that no one knows about.