I normally never touch the online component of games, but I've got to say, the point system with SF IV definitely has me addicted.  I haven't played SF since the SNES days, but I had to hit 500 BP before I went to bed.  The way they use that for matchmaking is great.  

Are the battle points like in Mario Kart Wii? Because that's probably the best matchmaking style I've ever seen.

Three cheers for addiction!

you get a number of points based on how well you do in a fight, generally between 30-50 from what I've seen.   Once you get a good lump sum they start throwing you in with a different set of guys around your skill.  Now if you loose a match however, there goes about 40 points.  So it's pretty well balanced.  If you're having a bad day, you'll be put in with an easier crowd, however if you're on fire you are sure to run into someone that'll put up a good show.