Let me start off by saying I don't know if this has been posted before me or spoken about in any way, that being said And if it was I still hope you take the time to read this real quick:::
One aspect of Halo that I personally loved was the ranking. Halo Reach brought a new ranking system via arena, and at first I was skeptical as many others were and wanted the 1-50 back. The only issue I have with the rankings is there is not one for every playlist. Playing Halo and striving to be a better player is something I believe all gamers can agree with, Since there is only one playlist that is "ranked" it leaves very limited area for showing your skill or for that matter even wanting to play. The ranking separates Halo from other games. If 343 could implement ratings in each playlist and have a "social" and "ranked"(arena) for each playlist I feel this game would become more competitive and at the same time still allow players to relax in a social match of their choosing as well.
Also if they would add some more forge maps into matchmaking it would add for some better gameplay.
If there were to be an arena for each playlist, a social playlist, and 2-3 more maps added to matchmaking, I believe that would increase the people playing Halo Reach and make it an overall better game.
Another addition that could be made would be: people who are to achieve the top percentage (1% ONYX) of arena in any playlist that there would be an incentive, ex- armor, special colors, name plates, ect.
Tell me what you think..