Apple seems to have issues launching MobileMe on me.com. There service was up and down during today, but is down right now at the time of writing this story.

Update:
Apple posted a brief statement that the MobileMe transition is underway but is taking longer than expected. On the DotMac support page you can see a services status of each MobileMe service.

Some smart guy already setup a site called IsMobileMeUp.com (Via Digg) that checks if the service is up and running.

Apple did not specify a specific launch day, but it was assumed that MobileMe will launch with the Apple iPhone 3G. Of course everybody is looking at me.com to see if it is up yet. The new communication service from Apple looks very pretty and easy to use. TUAW was able to collect screen-shots today from the times MobileMe was up.
MobileMe sells on the Apple Store for $99/year.