Best description of Crossfit I ever heard was "bunch of white people paying to be wore out". They mistake being tired with actually accomplishing something. As far as the actual workout? It's more or less fancy circuit training with an emphasis on the Olympic lifts for the strength building portion and rowing, running, etc.... The biggest problem is that almost all of the folks doing it have no idea how to properly plan it(especially the Olympic lifting parts). And most of the quality folks there have moved on or renounced the program do to back biting, etc...
And yes, Crossfit is plagued with both minor and major overuse injuries. Heck, they use to joke about puking or coming down with rhabdomyolysis.
The best part of Crossfit are the women of Crossfit, see them here-
http://wildgorillaman.blogspot.com/ .
Otherwise don't concern yourself with it.