No kidding. We've had communications about this from our readers, and I've had spotty service for a full 24 hours. There are also comments on the Apple Support boards about today's hiccups.
I made the mistake of using the MobileMe support Live Chat option yesterday, where I described my issues to 'Jason'. I told him I knew several people with the problem. His solution was for me to change my mail password. I typed back that I didn't see how that was the issue because I'd already told him I have the problem on 4 Apple devices (iPhone, desktop, MacBook Pro and iPad) and that the problem was happening on several networks, not just the home and office.
His response was that if I wasn't going to cooperate he was done, and he cut off the chat. Nice. Apple support is usually excellent, but MobileMe has had a lot of problems over the years, and I have consistently found MobileMe support to be often uninformed and defensive. As of this afternoon EDT Apple says it is fixed, and I hope that's true. Apple charges quite a lot for MobileMe services. The company could do better at reliability, and monitoring Apple support comments from users, instead of doubting a problem exists. I'm looking forward to the day when MobileMe 'just works.'