Here's a thread with industry insiders views:
http://comicbookresources.com/?page=article&id=22765
Particularly interesting is this guy, whose business is Disney publishing related:
Dan Vado of SLG Publishing, home of Disney properties “Haunted Mansion,” “Tron,” and “Gargoyles,” among others
NOTE: Despite being a Disney licensee, Vado wishes it to be known that he has no inside knowledge of the Marvel acquisition, and that his remarks should be taken strictly as his own opinions based on news reports.
“Marvel is the big winner here. My opinion, Disney overpaid (and Disney never over pays for anything) so it is obvious that Disney sees a huge licensing bonanza from the characters well down the line. Marvel books will, at some point, gain a stronger bookstore distribution partner should they decide to have their books sold through Harper.
“However it is worth pointing out that Disney does very little actual publishing of its own and has made most of its money by licensing characters out to third parties. It could be, again strictly conjecture here, that Marvel will end up being reduced to a licensing company and that its publishing will be scaled back dramatically as emphasis is put on content like movies and video games and less emphasis on things like publishing. Disney published its own line of comics years ago and pulled out...
That's a boatload of strict conjecture. It's needlessly alarmist too, coming from someone who wasn't in on the negotiations.
There are bound to be lots of benefits from the Disney deal. But I just don't see single comic books (as opposed to trade editions and hardcovers) gaining much more space in bookstores. That's not where the best customers go for their weekly fix.