Seriously, can someone count them out? Including fake-outs, secret imprisonments, amnesia, and in the other alternate Marvel universes. Any time where someone has declared his demise.
I was really looking forward to seeing more of Professor X in a better light similar to the movies. The guy has had some evil turns in the comics over the years. Such a disappointment. Couldn't they have killed someone else? I was rooting for Cyclops when the previews came out.
So my next question for comic scholars is, what is the longest period of time he has stayed dead? The last time I checked the Ultimate Universe he was still not living.
I feel I should also note the level of restrain Marvel has been showing by keeping Jean Grey dead for so long. Though that still may change.