Well, reading this one on the first reply:
"*In-game clan system - Not sure how it would work, possibly some sort of sub menu like instead of the clan tag option its the 'clan' option and you can invite members and if they accept their added to the list. Maybe would be useful if added with the stat tracker or some other feature."
- it is quite easy for this, if you've ever played battlefield 2: Modern Combat, you would see. Make a section where you can "Create a Clan" and you could name the clan, and put a motto.
-Once your clan is created, a new option comes up when you click start on someone's name that says "Recruit to Clan" Then that player would be sent a message via inbox, and would say "Accept, or Decline"
-To find a match it would be as simple as this: There would be "Rules" So to say... Like:
*Game Type:
*Map(s):
*Kill streaks Allowed? Yes/no
*Launchers allowed/ not allowed, and so on..
Now, the way it would be on a Leaderboard, would be of XP, not of wins, or losses, but of Experience.
Say for instance a really Good team in the leaderboard played a new team, and the new team lost. The New team would only loose around 3xp, while the good team won 3xp..
But now say a good team vs a good team went up, and one of them won.. Now the xp would be higher because they faced a so to say "good" Team..
Just some ideas