Preview at WWDC likely in June, followed by September launch.
.Mac Update Coming at August 7th Media Event?
Due to scheduled maintenance, .Mac members might be intermittently unable to access some .Mac services from 10 AM to 12 PM PDT on 08/07/2007. We apologize for any inconvenience.
Coincidentally, this time corresponds exactly to Apple's Media Event which is scheduled to take place on August 7th at 10AM PDT.
Steve Jobs had hinted that .Mac would see a refresh in the near future during a recent interview.
Walt: .Mac... you guys didn't really develop it.
Steve: I couldn't agree more, and we'll make up for lost time in the near future