I just downloaded it and installed it...

Autodesk® Revit® MEP 2011 Enhancements
 The list of supported video cards and drivers has been updated.
 Improves stability when opening a recovery file.
 Improves the selection of the proper fire damper size when inserted into an oval duct.
 Remembers the last justification when adding duct from the draw duct option within the right click menu.
 Corrects the creation of a small duct segment when a reducer is inserted due to a change in duct size.
 Improves stability when dragging a duct end to the connection point of hosted equipment.
 Improves the automatic joining of Cabletrays.
 Corrects the value produced for a calculated value column within Panel Schedules and Demand Factors.
 Allows the load value of a spare within a panel schedule to be editable.
 Corrects the display of Wire Size and Type properties to be “—“ for spares in panel schedule.
 Corrects the unit formatting of cells within the Load Summary of a Panel Schedule.
 Corrects the display of circuit number on wire tag when using circuit naming By Phase.
 Improves snapping an adapter to sprinklers when inserted from the project browser.
 Corrects the Air Changes per Hour calculation when running a heating cooling load analysis.
 Improves the connections produced by Routing Solution layouts of pipe or duct.
 Improves consistency of adding pipe, duct, conduit and cabletray when snapping to non-MEP elements.