Yeah that was a really good episode! I downloaded it (torrent) and watched it the same night it was out and I've spent most of the following days showing to friends that are still addicted to WoW. I'm happy and proud to say that I've quit Wow a few months ago after an exhilarating 9-month play with no RealLife®.
You might think it's funny but even though South Park is a extreme or borderline parody it still reflects big chunks of the truth. I've had a friend who actually looked exactly like that "evil player" in that episode. A 35 year old guy who started playing WoW about a year ago, quit university, got a job & lost it during the first month, grew about 20 kgs fatter and his place was littered always with thrash food and empty cans.

I'm not saying that WoW will turn you into a no-RL-mutant but it can be extremely dangerous of weak or susceptible characters.