In case you haven't heard (and you're a Revit MEP user), a couple of manufacturers have gotten on the bus with their own content. One is McQuay (http://www.mcquay.com/McQuay/BIM/Revit-BIMFiles) for air side components. Watch the shared parameters file - while it's nice they included this, be careful that you don't overwrite your own parameters. Look at theirs first if you haven't customized this. I don't know about an Autodesk endorsement for their products, but they're still worthy of checking out and using where possible.
Titus has a plug in that goes directly into Revit:
A couple of our TE's have been checking this out, I don't think they're gotten everything working 100% with it, but as with McQuay it bears inspecting.
Trane has had some parts up for while:
Links are in the lower right corner of the page.
It'll be interesting to see what other manufacturers get on the bus this way - these guys are already getting a leg up on the competition.
Happy downloading - David B.
An update - David from McQuay responds about the endorsement part - read on, it's a helpful explanation - thanks - David B.