I like this. Maybe similar to the prestige systems in games, and it shows your dedication to playing a class and allows you to keep it up. I like the idea of having new taunts and special skins available to tiered characters. Even stars next to them in the score board so you could see you dominated a 3* Montana.
Borderlands had a good prestige system, but the CoD prestige system could actually work with all the titles and icons etc. Even have a variation of Legendary items for other levels.

