Not that it was hard to see it coming
It's basically a map pack for MW2:
The best part is that that engine is still just a heavily modified Quake 3 engine. At this point modified so much as to be almost unrecognizable, but there's still legacy code in there. A testament to how good John Carmack used to be before he decided building rockets was more fun than building video games.
Professional reviewers are giving it high scores, gamers are giving it low scores. The high scores are due in no small part to bribes and threats to cut funding. No joke. This sort of back room bullshit has been documented in the gaming industry for several years. This is why we don't trust review sites, folks. Giantbomb.com being an exception.