What do you think this incident reads like in Vivendi's annual report? I'm thinking "We made a few more mountains of money with the enormously successful release of Diablo 3. Fans love it and monetization is six times previous records for the series a per-copy-sold basis or 200 times higher per copy played."
WoW also had launch issues. Players complained. Money hats were made.
In the near term Blizzard isn't going to be going out of business, nor is it going to have a shortage of money hats. But make no mistake, this is a serious issue and it has tarnished their reputation. They still have plenty of excess reputation at the moment but if they continue to take a cavalier attitude towards customer satisfaction then there will be another incident like this, and another, and another, until it really starts hurting their bottom line in a way they can't ignore.
Did it really tarnish their reputation when SC2, WoW, or DiabloII launched? It's such a transient thing that seriously suspect that they could do this forever and never effect sales in the slightest.
WoW also had launch issues. Players complained. Money hats were made.