Apple today announced that its online service .Mac will be replaced with MobileMe.

Apple has posted an article aimed at .Mac users to help them understand the transition.

This article helps current .Mac members better understand what to expect from the upcoming MobileMe upgrade. When MobileMe becomes available, this article will be updated with more details to help upgraded members get started with the new service. You may want to bookmark this article and refer back to it when MobileMe goes live.

In short the article outlines that your .Mac account will work as it did before, but you’ll have a choice of using either username@mac.com or username@me.com. If you have aliases setup at .Mac they will continue to work as well. All your .Mac websites will continue to work at both mac.com and me.com.