Claremont did have a spectacular run of 20yrs. Some writers burn out just like pro athletes do in sports. Look at a guy like Frank Miller, he was one of the top writers in comics now I would go near anything he touches. His stuff is a joke now. El Bastardo makes a great point, the editorial staff failed to realize Claremont was past his prime, they've been burned twice by him now. The first time in 2000 then again in 2004. X-Men Forever was another bust with small audience. I never read his FF but I don't think it was well received. It's also important to remember that Claremont also had plenty of successful runs along side his first X-Men run, Excalibur vol 1, Wolverine vol 1, The New Mutants vol 1, Marvel Tales and Marvel Team-Up vol 1( the good one). He's had great success in his career, just not lately.
As for Iceman making the cross over....it's a waste of time. When AoA Iceman and his tremendous control of his abilities were introduced, fans thought "Hey, why can't 616 Iceman be cool like that?" So, after AoA ended, Iceman received a heavy push with his powers straight through Operation Zero Tolerance. Ever since, he's been cast to the corner of Utopia that I call the "Island of Misfit Toys". Use the Iceman you have that's doing nothing, don't add another. It's the same reason I don't think AoA Jean will cross-over, "our" Jean's return has been constantly looming over our heads. Sabertooth on the other hand, his head was chopped off. The AoA Creed character is structured differently. He's still cunning but not as psychotic. Watching him interact with the 616 X-Men would be more interesting.
