The Anaheim Convention Center definitely has the floor space. WonderCon used about 1/4 of the main floor this weekend (all of Hall D, unlike Wizard in 2010, which only used about half to two-thirds of it), not counting registration downstairs.
Rooms for programming might be a problem. As near as I can tell, WonderCon used all the meeting rooms on level 2, and the large ballroom that takes up most of level 3. The Arena might be a good replacement for San Diego’s Hall H, but for the smaller panels they’d have to spill over into the nearby hotels. Fortunately, those hotels are next to the convention center, not at opposite ends or across a railroad like in San Diego.
Parking was the major breakdown this year, and Comic-Con will need even more. (I’d guess a lot of the people at the volleyball and cheer competitions were staying in hotels from out of town, or bused in from closer schools.) I suspect if they can use the stadium lot all four days and direct people to it clearly (including signs between the freeway and convention center letting people know that the convention lot is full, and accurate directional signs all the way to the stadium lot), it will probably be all right.
Food could be a problem, but it’s easily solved by bringing in food trucks or encouraging people to walk a few minutes. You know…like we do in San Diego. (Though hotel restaurants and a half-empty mall have nothing on the Gaslamp District.)
Hotels, to me, are the biggest open question. Most of the pro-Comic-Con-in-Anaheim articles I’ve seen sort of gloss over the fact that Disneyland is right across the street, or use it to bolster the claim that there are lots of hotels.
But you know, Disneyland visitors are going to be using those hotels, too. Especially during the height of summer.
Update 2017: The convention center is building a whole new wing with 200K more square feet. WonderCon is now using 3/4 of the main floor for the exhibit hall, the remaining section for registration, and programming is spilling over into the Hilton. There are a lot of new hotels in the same block and the next one over. Restaurants are about the same, but they’ve brought in more food trucks every year. Parking’s still a problem, though.
See Also: Convention Photos & Write-Ups