I think crossfit is a great idea in general, and those that are criticizing it are being a bit disingenuous. If you are a serious athlete, you probably have a trainer and a nutritionist to help you out with your training, and I doubt crossfit is being specifically marketed to these rare individuals. People too often think they should do what athletes do, forgetting the often excellent genetics and already high level fitness attributes that athletes possess.
Crossfit, IMO, is very well suited to martial arts training. It is focused on building a number of key attributes, rather than specializing in one area. It is certainly true that martial artists need many attributes- explosiveness, quickness, flexibility, stamina etc. etc. For this, crossfit seems to fit the bill.
Of course, you don't have to follow the workouts blindly irrespective of your own strengths and weaknesses or your goals. And you can certainly mix workouts like "fran" with other fitness activities. For me, even if I was doing a crossfit workout once or twice a week, I would also include a maximum strength workout, because that just happens to be something I like to focus on.
T-nation did an article on crossfit a while back, and generally had positive things to say about it:http://www.tmuscle.com/free_online_artic..._about_crossfit
Lastly, if you're really enjoying it and feeling like you're getting a good benefit, then it's probably a good thing!