when I play it (several times a week 6-10pm central) I would guess my games are more than 85% full - but there is the rare occassion you'll be on a map and the team is vastly outnumbered. when that happens I just quit that map and launch it again and I get connected to a more balanced game.
I play every now and then, but I can say the community is very much alive. I went through a few rounds before posting this. I haven't played much since the Bad Company 2 beta which was quite addicting. Its hard to go back lol