(Updated 10/31- Now with more teasery goodness.)  I checked my email box like I do every Friday for some clips for the next episode.  Imagine my shock when Warner Brothers instead sent a link for critics and bloggers only to see in ITS ENTIRETY next Thursday's episode, "Changing Channels."  I needed to get some coherent thoughts together and come up with a non-spoilery review, but a day later I managed.     

Holy crap!!!!  That's nothing what I expected.  Nothing!  It's incredible.  Of course I don't want to be guilty of setting lofty expectations, but there's a reveal in there that blew me away.  Heck, the whole episode blew me away.  (Below is a list of teasers.  I promise, no massive spoilers.  I'm basing these comments on the fact that you've already seen the preview and have an idea of what's happening).

********************************************** You've been warned and yes, even the comments section is fair game. **************************

-  This is a Mytharc episode.  A very important one.  Castiel is in it.  As is The Trickster, but considering the episode description says that, I don't consider that part a spoiler.  As we would expect, Richard Speight Jr. does not disappoint.
-  This plays a lot like "Mystery Spot."  Funny to start off with and then it turns dark.  It's also as well done as "Mystery Spot" but not as fast paced.   
-  It starts off with the sitcom and it's huge goofy fun. 
-  There's a new mock episode intro ala "The Monster At The End Of This Book," and it's the craziest damned thing I've ever seen on this show.
-  They do spend a fair amount of time in the medical show, Dr. Sexy MD.  Yes, that's the exact name used by the publisher in "The Monster At the End of This Book."  It is SO a Grey's Anatomy spoof.  Dean is funny in this bit for reasons you'll see early on and Sam is forced to play surgeon.   
-  I especially died laughing over a little Public Service Announcement that made Sam's issues with the clap this past episode seem tame. 
-  The CSI Miami thing is brilliant, and both brothers jump into the role a bit too much.  There's a line that Dean says about wearing sunglasses at night that had me falling off the couch in laughter. 
-  One of the shows is a spoof on Knight Rider.  So the Impala is the Kitt car, that leaves one brother to be the driver and the other...well, figure it out. 
-  One burning fandom question about "Mystery Spot" is answered.  
-  Don't be fooled by the goofy TV Land stuff.  There's some heavy stuff in this episode.  

No wonder Warner Brothers wanted to get the buzz out.  Either that or they were testing a new way to streaming previews like this online instead of sending discs.  I like it!  "Changing Channels" is a must see.  No filler here.