Sharky has published "XNA Collision Detection for 3D models - Part 1". The first article of a two part series where he tells from a "code warrior" experience the path he has being following so as to implement a precise yet robust collision detection system in his game: Air Legends.
This is an interesting read since it's a common problem developers face when dealing with collision as rotating AABB -in case you decide to go this way- could bring performance issues, possibly leading in the end to the use of other techniques like bounding spheres (i.e.: read the comments on this post).
I cannot wait for a new release of Air Legends (and the radar), one of the first games that were and are still in development using XNA ... and of course, fun to play too ... ;)