The Hollywood Reporter posted an article called Power Lawyers: How 'Star Wars' Nerds Sold Lucasfilm to Disney which details all sorts of fun little tidbits, like how they went and confirmed Lucasfilm really did own all the copyrights and trademarks and what have you for hundreds of characters which are now in the hands of the House of Mouse.
A notable quotable:
“George had a history of associations with different people who had different rights, so sorting that all out was our biggest challenge,” says McCarthy. “Like anything else in the entertainment industry, if something becomes successful, everybody puts their hand up. So, over the years, there were people who put up their hands.”
Also:
"Working with Lucas’ lawyers at Latham & Watkins, McCarthy's team researched all copyright assignments and distribution agreements. The team eventually determined that all the important copyrights were intact and available to sell to Disney, save for distribution rights for the original Star Wars film, which 20th Century Fox maintains even after Disney’s acquisition of Lucasfilm closed Oct. 30."