Haha, I was amongst those droves...
Yeah, there are tons of ranked, populated servers...no worries there. And I think patch 1.5 includes some of the expansion material (new maps and weapons + "You got it boss" in a fake EU accent. When you hear it you'll know.) It's still as fun as day one and definitely worth buying. I have to say though, that any game is easily 10x as fun if you know who you're playing with...so LAN it up!