As part of the deprecation plan for Mapplets we'll shortly be switching from rendering Mapplets within Maps, to a dedicated Mapplets page. In conjunction, the directory will be closed, and links to Mapplets will be removed.
Bookmarks for existing Mapplets will continue to work. They'll be automatically redirected to new Mapplets page for relevant Mapplet. However because Mapplets page isn't part of the Maps app, Mapplets will no longer have access to Maps user profiles[…]
The above changes will be made on or shortly after Wednesday December 8th 2010.
If you've added one or more mapplets to "My Maps" and you want to use them even after the links are removed, find them in the Maps Directory, convert their URLs and bookmark them. For e.g., replace: