Hmmmm... my main gripe with the current "Kitty alone against the Hellfire Club" story is that she isnt. Theres a whole X-Men team there in the mansion, and other X-Men hanging about, and 198 other mutants and numerous huge sentinals all hanging about the front lawn.
Even the New X-Men team is nowhere to be seen, which is even weirder, as without them, the student body in Astonishing seems to only consist of the same 2-3 kids most of the time.
The other X-Men are there.. its proven by the fact theyre in every other X-Men comic. Whedon really should at least try to come up with an excuse why theyre not around, even just saying theyre out on missions around the world would be enough. Its kinda hard to fit his book into continuity if he wont aknowledge that theyre there.