I honestly can't see any companies Disney should acquire at this juncture. Remember, each of the companies Disney has bought have incredible movie franchises, or even are so famous that they're IP in themselves. Pixar, Marvel, and SW are each juggernauts in their field. There's few things quite like them. Pirates of the Caribbean and WDA are comparable, but they're rare.
Compare that to any other brand, and there's just a handful. Harry Potter, Lord of the Rings, and James Bond are some of the most notable. Most everyone of those is owned by a company that strongly grasps on to it, and is so large that it would be prohibitively difficult to be acquired by WDC.
What Disney could do is acquire Time Warner with a partner, and then sift through all the companies and figure out what they both want to keep. Between its strong cable and movie footprint, Disney could find some interesting properties. It would either own or have shares in Harry Potter and Lord of the Rings, and Disney could hold onto many of the cable channels, and perhaps hold onto the movie studio.
CNN could be spun off, DC Comics could be spun off, and HBO would likely be spun off too. (While it's undoubtably a powerful brand and property, I don't see Iger selling Game of Thrones next to Mickey Mouse and Captain America) Though all of this requires a deep deal of coordination and partner that's willing to play ball with them. I think honestly it would be more hassle than it's worth. Disney has been on a role recently, and acquiring that Company doesn't make sense.
The only other company like Lucasfilm or Marvel is Danjaq, and I doubt we'll see the family give up control anytime soon.
Now if Disney wanted to spend 2-3 Billion on getting Spiderman back, that would be much more believable. I think there'd be great upside potential there. It would also reinforce the characters place in the cinematic universe to great effect.