For me, the fuss was all about how the movie didn't completely and utterly SUCK. Three outta four comic book movies will be horrible wastes of time (I think that ratio also applies to Stephen King flicks). The fact that someone made a heavy hitter like X-Men into a good and faithful-to-its-source-material movie is simply amazing.
So far, my list of good comic book movies is as follows:
X-Men
Batman
Batman Returns
Conan the Barbarian
Heavy Metal
Blade
Out of all those, X-Men is the second-closest (Conan being the first) movie to capturing the feel of the comic. It stayed true to the characters (the main ones, anyway). That's an even rarer thing. And the differences in character it did have were not that far off.
I like to argue about Mystique. In the comics, she's a top-notch assassin who's extremely hard to catch-up with. The big arguments I've heard against her movie counterpart are that she's a wire-happy kung-fu-slingin evil bitch. I bet she could do a lot of that stuff anyway (though that is rationalizing, I admit). The only difference I really saw was a lack of guns and clothes...But do ya really miss em?
Sabertooth was a bit...lacking, though. He's not exactly chatty in the comics, but I always looked at him like I do Hannibal Lector: something evil behind those eyes. Not just a physical rage, so much, but a devious intellect. Check out X-Men #32, I think. Sabes is in the custody of the X-Men and he reveals a bit of Gambit's past. The whole thing reminded me of Silence of the Lambs. Face mask and all. Wolverine #92 had more of that in it. He and Logan duke it out and Sabes is just pushing Logan to murder. The frosting on the cake, though, has gotta be his 4-part series (with Mark Texiara's beautiful cover art). Sabertooth is a f*cking bad man, there.
Anyway, Toad was way-off base so far as looks go, but not enough of his character was shown to pass judgement.
Storm was kinda wasted. Not even delving into that whole "what happens to a Toad" line...African goddess makes it into a movie, and all she does is get her ass kicked by every bad guy she sees. Sad.
Continuity was way off, but they didn't exactly have 30 years to play with, did they?
So far as the sequel goes, I'm not sure how far audiences are willing to go with giant robots with jet boots smashing around New York...