The transition should take place over the "next several months."

It's a sad day for longstanding Blizzard fans, but you could also say that it's overdue. The Battle.net name is a holdover from the days when GameSpy, TEN and other third-party services were virtually necessary to join online games for those players not intimately familiar with IP addresses. They lost their main reason for being when many games started treating multiplayer as a central feature, and broadband internet access made it almost trivially easy to find and join matches.