When Disney purchased Marvel, they knew they were, in a way, pulling a “save the hooker with the heart of gold” routine, simply because Marvel had sold so many pieces of itself over the years. While Disney isn’t likely to wrestle control of some of the biggies like X-Men and Fantastic Four from the big bad Rothman, they have come to an agreement with Paramount to round off their control of The Avengers stable.
As it stood, Paramount was still on track to distribute the third Iron Man film, as well as the quickly assembling Avengers film- for a nice $115 million dollar transfer fee though, Paramount was more than happy to let Disney reclaim the full rights to those titles. Disney is obviously hot to run those sequels through their own multi-platform marketing machine as not only will they be paying off Paramount with the initial fee, but they’ll be giving them points on the backend.
Ultimately this means very little to you the viewer beyond Disney setting the date for Iron Man 3 as May 3rd, 2013 (sooner than I expected, honestly), with no word on their intentions of remaining loyal or not to Paramount’s May 4th, 2012 date for The Avengers.
There are a few more corporate-type quotes and nitty-gritty details to be mined from the Variety story (if you can surmount the paywall) but the thing to take away from this is that Disney is in the Marvel business for reals, and the Mouse House has and may actually use their resources to call back many of the wayward characters in a way Marvel proper has never been able.