I wouldn't say the film was completely untrue to the comics, there were merely slight changes that only a serious X-Men dork would get bent out of shape about. I wasn't mad and nor was my uber-Comic geek friend that I saw it with. This is essentially going to be a prequel trilogy to the first three X-Men films (omitting the Wolverine movie) so I'm sure the little changes to the real deal story is going to make sense in the long run.
While I loved Thor, this has already beaten it and set the bar very high for Green Lantern and Captain America.
Also, technically Nightcrawler's mom is in it too. But she's been in all of them so far.
oh and the Wolverine cameo was the so good.