In marvel Mutant is sombody that NATURE made into a metahuman. IE their genetics made them have their power. all the others are simply Metahumans. In most comics it's considered normal to refer to most heros (hawkeye, batman being human aren't) as metahumans. Ultimatly I'm not an "as they come out" comic reader. I wait and pick up the trades. thus I can't say what exactly is going on in civil war, but I'm sure the guys over at the COH boards know.
Also from what I can tell, the civil war will mainly revolve around spidey. Because Bindis is a jerk when it comes to storylines and his favorite characters (who seem to be Wolverine, spiderman, Cap America, Ironman, and Colossus. I think he HATES Kitty Pryde, Beast (he killed beast off real real fast in Xmen.) she hulk, and night crawler.)
House of M was essencially Bindis version of making marvel continuity his. because of how he did it he could depower who he wanted and empower the others. He's OFFICIALLY made Wolverines name Jim Howlett, and after the house of M Wolvie is supposed to remember his entire life. but I have yet to see anything that indicates that Chris Claremont or other writers for Xmen really care for that. thus right now it seems like a better time to pay attention to DC rather than Marvel's continuity.
With Infinite Crisis the just put everything back to the seperate earths. IE we get earth bound god superman back along with all those wackey different stories from different continuities... Elseworlds get their own version of earth, that sort of thing. Also the Identity crisis spun things topsey turvy causing the JLA to break up and now we have Hal Jordan back among the green lanterns. (he's the one who went bezerk in 1994). so yeah... comics are still wackey but DC isn't going insane and changing the status quo THAT BAD.
Now for the movie... I saw a really messed up version of a plotline for it and hold out hope.