The official announcement of .Mac was made this morning in Steve Jobs' Mac World keynote speech. .Mac is their internet services bundle formerly known as iTools.
Why the name change?
1) Because they significantly updated the features, including antivirus software, more storage (now it's 100MB) and backup software.
2) Because its name is a play on Microsoft's .Net campaign of internet services. (hmm... Apple copying m$ for a change, I guess anything really can happen.)
3) Because they're trying to draw attention away from the recent major price hike for these services($0/year->$100/year, OUCH!).
This could prove to be a large mistake. While they currently have 2.2 million iTools users, it is highly unlikely that the majority will stay as most simply use it for the free @mac.com e-mail address. As a current iTools user who REALLY likes having an @mac.com e-mail address I might bite the bullet and pay for the service, but I sure as hell would rather not.