I have seen this feature when I was watching Summer Of NHibernate tutorial videos; is it possible to copy some of of the references of a project in the solution and paste them i
You can use PowerCommands for doing it.
(see also Sara Ford's Blog)
You can also try VSCommands 2010 extension which doesn't suffer from errors affecting PowerCommands when pasting references.
project files are just xml files. you can open them in a text editor and carefully copy the references.