Wow, Mangini huh? He can definitely do just about anything with either hand or foot. But I dunno, he doesn't really seem to groove very well. Check out those covers he does on YouTube. Cult of Personality and Brick House are completely awful. Hes fast and technical, has a big name and most likely has the gig at this point since he cancelled his classes. He also went to Berklee around the same time as the other DT guys so that would probably be a no-brainer. Hell, his name is Mike so they don't even have to think twice about the name of their drummer! hahaha
I don't know, Gavin Harrison hasn't been mentioned much on the forum and know a friend who saw all the members of DT at the NY Porcupine Tree show right around when Portnoy quit. Tweets around the time of the show confirm it on the DT members. He would have a groove and feel and be able to really bring DT to a new level IMHO.
Charlie Zeleny would still be the best option in my book especially if they wanted to go with a semi unknown guy. But they didn't even ask him it sounds like which is a drag since he does have some underground prog street cred with Blotted Science and Behold the Arctopus. Those vids of Dream Theater covers on his YouTube were out of control. His mainpage video on his YouTube had one of the most melodic drum solos with ostinatos I've heard in a while too actually. Kicks Mangini's ass in musicality. The dude is also the most versatile drummer I've heard since he actually can swing, groove, rock, play metal, blast beats and do Portnoy's parts spot on perfect.
The other dude that is out of control is Bobby Jarzombek, but its been confirmed he was out of town during the auditions. He could do anything any one of the other drummers could do and do it with cymbals behind his back! Best strict metal/prog drummer I've heard. So tight and amazing. He totally looks metal, would bring DT to the highest level and has tons of credits to boot (Fates Warning, Halford, Riot, Iced Earth & more). The stuff he does on his instructional DVD is insane as is his stuff with his brother Ron in Spastic Ink.
But since Charlie Z and Bobby Jarzombek are out, I would much prefer Lang or John Macaluso. They are more badass and hit the drums harder than most of the other guys. Neither of them have a goofy image like Marco Minnemann either. Virgil is too fusiony in my opinion, Mangini doesn't groove hard enough, Peter Wildoer is not tight enough or together enough as a player and Aquiles Priester is completely boring, monotone and just used Superior Drummer 2.0 over all the clips in his videos (using the mics to trigger a software program to give his drums that tone).
Watch, Dream Theater will pull a fast one and get Gene Hoglan to join and blow all of our minds! DT is the only band he hasn't played for really...(not really, but you know what I mean).