Apple's MobileMe communication service still has some serious issues. For several days now 1% of MobileMe members cannot access MobileMe Mail.

Apple's support says that on July 18th a serious issue happened with one of Apple's MobileMe mail servers.
This issue is currently affecting approximately 1% of MobileMe members. Affected members are unable to send or receive email at www.me.com or access email using any email client software such as Mail on a Mac or Microsoft Outlook on a PC. Now it is the 24th. I have no idea how fixing this situation could take that long. Unless they have sent in forensic to restore lost account data on some hard-drives. For a paid service it is totally unacceptable to not get the service back for several days. Because it is email, this must be very hurtful to the MobileMe customers affected.
More details in this Apple Support memo.

Apple had also serious launch issues with MobileMe, that triggered the company to apologize and hand out one free month of service.