This will give you a summary of nodes you have installed in your Dynamo Packages folder.
Source: https://twitter.com/lukeyjohnson/status/657367093113933824
Bakery
Remove First Revision from Each Sheet
This node takes a Sheet list as input, and finds the first (earliest) Revision that is placed on each individual Sheet. Then it removes that Revision from the Sheet. This node may be useful for project cleanup.
Add Most Recent Revision to Sheet
This node takes a Sheet list as input and applies the most recent Revision (last Revision entry) to those Sheets.
RVT Information for All RVTs in a Folder
This node takes a Folder as an Input, and then checks each file in that folder for its RVT Build number and Worksharing Status:
Get External File References and Details
This node uses Python to access the File Reference details for the currently opened Revit file using the API. It also relies upon another node that uses a Python import to get the System file Date Modified information using the Path gained from the Revit API.
Source: https://twitter.com/lukeyjohnson/status/661019299608264705
Collect Tag Elements in Specific View and Send Ids to Clipboard
Check Specific Shared Parameter has correct GUID
This will query the elements in the model, get their Type, then compare the GUID of a given Shared Parameter against a known GUID.
via https://twitter.com/lukeyjohnson/status/629178849834594304
MEP Elements to Geometry using NURBS
Create Floors from Rooms
Takes Revit room Elements and creates Revit floor Elements. Various versions are available, currently at v4.
Source: http://whatrevitwants.blogspot.com.au/2015/10/create-floors-from-rooms-across.html
XPATH Expression Find for Element Tree
Update:
New version allows traversal of XML sub-elements, as shown below.
Traverse Element Tree
Description:
A tool that allows extracting specific data from an XML file.
Source: http://whatrevitwants.blogspot.com.au/2015/11/read-xml-files-and-use-in-revit-with.html
Dynamo Nodes 