I think you could probably have some pretty nice "superhero" based iPad games, but I really don't think you could handle the complexity of something like CoH on such relatively tiny screens. Let's just say I would find it hard trying to play CoH on an iPad after being used to playing it on my 27" monitor at home. 
And as far as other support apps for CoH that'd be fine. But once again I would pretty much -never- expect see an official offline costume designer for CoH for the same reasons we haven't had one all along. In case you aren't aware there were some lawsuit troubles years ago with Marvel which (apparently) effectively barred our Devs from allowing any offline costume apps to exist.
Loth 50 Fire/Rad Controller [1392 Badges] [300 non-AE Souvenirs]
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--{=====> Virtue ♀
So I saw that there was a swords-and-sorcery style MMORPG released for the iPad, meant to compete with or mimic the largest MMO currently out. I don't know what it would be like to play CoH on an iPad (I'm guessing tough) but it raises an interesting idea: are there iPhone or iPad apps that could interface with CoH?
A Mids-compatible app (maybe sync with Dropbox or MobileMe?) comes to mind; an offline costume designer with desktop file compatibility would also be pretty cool.
Ideally, the tank will die precisely as everyone else starts fighting, allowing aggro to be spread evenly among the blaster. -seebs, "How to Suck at CoH/CoV" Guide