Here are few features I liked from the VS 2010 Power Tools released last week :
Visual Studio 2010 Pro Power Tools
- Close button in tab as well
- Pinned Tabs
- Searchable Add Reference Dialog
- Triple Click to select a line
- Align Assignments (Ctrl + Alt + ] )
Visual Studio 2010 SharePoint Power Tools
- Sandbox Visual Webpart
(Although there are few limitations which are mentioned in the tool description tab here)