Gawd, I'm still one freakinn' acheivement from 100 in Halo3. Frickin' "Steppin' Razor."
Oh for those Halophiles out there, Bungie over the weekend announced a new system for ranking! They as yet have not said when it will take effect but it's coming SOON.
Here's the link (scroll down halfway or so until you see "AU Deuce" (which stands for Auto-Update 2): http://www.bungie.net/News/content.aspx?type=topnews&cid=14994
Basically instead of carrying your overall rank into each playlist you will now have a different rank PER PLAYLIST. This includes Ranked and Social. It depends solely on the amount of WINS you have in each category that determines your military rank. Skill now has NO bearing on that. In fact once you reach 600 XP in any given playlist you become a General in that SPECIFIC playlist.
There's more to it than that, so go and read the info in the link.
For me I see it as a good thing. It will encourage those who want to rank up in everything to play all those different playlists. For people like me who are perpetually stuck at Staff Captain, it will mean in some playlists (as in my case Ranked Team Slayer) we'll get a military rank upgrade. Much of my XP is in Ranked Slayer so I may bolt up from the lowly Staff Captain to Brigadier or General. But it also means in those playlists that I have virtually NO XP, that I could be a Sgt or even a recruit. Of course this applies to everyone.
Your OVERALL rank will not change with the update, not will your skill. Overall XP will be accounted for and your overall rank will go up with that and skill. So basically Bungie has just further subdivided the ranking.
Again noone loses their overall ranking and noone loses their overall skill. Just the individual playlist ranks will change, NOT the individual skill ranks as those are already in place.