35% of UpToDate topics are updated every four months. The editors select a small number of the most important updates and share them via "What's new" page. These selections are changed with each major release of UpToDate, in March, July and November. See these updates by clicking on the specialty you are interested in.
The page does not provide RSS feed for the different specialties. One solution is to copy/paste the URL address of each subspecialty page you are interested in the Google Reader "Add a subscription" field (top left corner). Google Reader will automatically create a RSS feed from this "feedless" page.
UTD Contents: What's New