By far the best decision, and I strongly hope this gets read by 343, is to bring back the halo 2 ranking system, as described in the first post.
Halo 3 was a disaster, and halo reach's ranking system is non-existent. Let's finally get something that works again.
Also, what about the possibility of more than 1 ranking system? Perhaps having a second one based on something else?
The more stats, the better. Make Halo the leader, the pioneer of gaming by doing things that have never been done. Make stats for group of people, stats for a person when he plays with certain others(conditional stats), etc, etc. I know I'd love to see that stuff, people would eat it up and keep them involved....I got kinda off topic...oh well, the curse of enthusiasm