There is no software you have to download to get the updates. Since MobileMe is a hosted service, Apple made all of the changes on the servers and applications without affecting customers. The changes affect all of the components within the service.
MobileMe Mail received the most updates, fixing problems like keyboard shortcuts not behaving as expected; messages not being removed from the Drafts folder after being sent; improved performance when Junk Mail Filtering is enabled; and improved performance when first logging into MobileMe Mail.
The Calendar application improved performance in several areas and resolved an issue where event editors would partially display in some browsers. The ability to export contacts as vCards has been re-enabled and the experience of viewing MobileMe Galleries has been improved.
The MobileMe launch was fraught with problems from the very beginning. Shortly after its launch, Apple apologized for the continuing problems and offered members a 30-day addition.
Another extension, this time for 60-days, was offered in August when Steve Jobs said in a memo to employees that the service “not up to Apple’s standards.” Jobs also said that Eddy Cue, Apple’s vice president of iTunes, was taking over management of the service.
A complete list of changes for the latest MobileMe update are available from Apple’s Web site.