I was reading something and (I am sure that you already know this) but It looks like Gracenote launched Gracenote Open Developer Program.
http://www.gracenote.com/company/faq/developer/
http://www.gracenote.com/press/02/15/2013/
Although I don't know if Winamp can be considered a "non-commercial developer". But. I hope that this helps Winamp keep Gracenote as it's look up database and maybe even add some of the other features gracenote offers.