I completely agree with David-- if we don't see an item called the Sword of 1,000 Truths (or the Bow of 1,000 Lies, which is supposedly what the bow Kenny was using is called) in the expansion, I'll be greatly disappointed. Of course, maybe we don't have to wait that long: Thundgot on the EU forums says the sword currently drops "from boars in Elywnn Forest." Unfortunately, a four-man raid is required. If you want the model for the sword, you could always pick up The Hungering Cold.
TV.ign drops a review of the episode (they liked it), and the forums over at WorldofWar.net have an interesting theory: Cartman says it will take them "7 weeks, 5 days, 13 hours, and 20 minutes" to become uber enough to beat the bad guy, which, if you add it up from the time the episode aired on October 4th, puts the date at November 28th. Did Blizzard hide a BC release date hint in there? Of course, when Stan's dad shows up at the Best Buy, the price shown is $49.99, and we all know that's not true.
Finally, I'm not sure if we've mentioned this here yet, but most of the machinima for the show was actually done by Rufus Cubed, the studio behind "The Return"-- also the guys that were hired by Blizzard to make the Eastern Plaguelands PVP trailer. Not only is this show the first mainstream TV show to use the word "pwnage," it's a huge success for machinima in general.