If you are on subscription, Autodesk released a couple of content updates - one for Revit MEP 2010 and one for AutoCAD MEP 2010 - last month. To download these, log into your subscription center site (http://subscription.autodesk.com/) and browse to the Product Add-ons Section - you can choose to download either file (both are ZIP exe files, so make sure your firewall allows the download of executables). Run the EXE by double clicking it.
The RMEP file is 27mb and adds electrical content for low-voltage systems; the ACAD MEP file is 110mb, and includes "300 new pipe fittings to help mechanical, electrical, and plumbing (MEP) professionals create pipe design models and drawings for projects in the United States", which includes Cast Iron (Bell and Spigot, Hubless), Ductile Iron (Flanged, Mechanical Joint, Push On), HDPE (Fusion), Plastic (Hub) and Steel (Grooved).
There is also a Revit Structural Library download as well, for guys that hold the buildings up...
Later - David B.