A lot of the parts are available on Ed Sparks' site
http://www.firstcadlibrary.com/ in Inv5 format (thanks, Ed!).
I'd be surprised if Autodesk has any plans to release Inv5 files of the new parts. It is a fair amount of work to create the files, so we should be glad they support us to start with. Don't forget they are in business to make a profit and they have no vested interest in helping us delay upgrading our software!
Not that I want to be an apologist for Autodesk, but I do believe in capitalism.