http://research.microsoft.com/en-us/projects/trueskill/
Worked absolutely amazing for Halo 3, and they have had decent success with many of the online sports franchises.
Let's face it. Warzone randoms against pre-mades = ticking time bomb until end of subscriptions. Randoms will lose 19 times out of 20. It's an MMO, so of course group PVP needs to be the end game. However, there needs to be a way to keep lvl 50's that do not group in the subscription base.
True Skill, first of all, would force pre-mades to play pre-mades and singles to play singles, or at least make teams have similar mixes. The next and most important effect would be to invisibly rank everyone and try and make the closest matches possible, whether as groups or individuals. The one downside is search times, but Bioware could play with some of the equation to reduce those to a certain extent.
Halo figured this out a long time ago...with a crude system in Halo 2 and full Trueskill in Halo 3. They tried to loosen the Trueskill restrictions for Halo Reach and have seen it absolutely kill it's popularity online and even to a certain extent with MLG.
If someone loses 75+% of the time, it's not long before their time here is finished.