I don't think Benny is going to become a third wheel. What we were shown in this episode was that life without purpose (or support) is just survival. The vampirates (loved that term) have been doing the same thing for centuries and only really excelled at destroying human lives. Without being a hunter Sam was lost as to what to do with himself, until he found the simple joy in fixing things around the motel and helping out the motel owner's kid. I can kind of see where Edlund was going with this in the script, and we'll definitely know in a few more episodes. 

I do think that Benny will sacrifice himself to save Dean and bring back Castiel. Benny has nothing left here, and believes he was better off in Purgatory anyway. As with all of Edlund's scripts, they usually are the setup for the next few episodes to follow and give us the direction the series is going in subtle hints that aren't all together clear until the entire puzzle is put together.

 I think this is flawed from the start by calling Bobby a "third wheel".  Come on, the man was their second father, and, at least to me, was much more interesting than John Winchester ever was.  He was also around a lot longer than John, so maybe John just needed more time to be more interesting, but oh well.  The term "third wheel" pretty much implies that the character is not needed or wanted by the other characters.  This was never so.  They relied on Bobby many times, and he was always there to call them idgits and get them on the right path.  And I love the layers they established over the years - how the hell is such a glorious redneck fluent in Japanese?  Why did he use tongue when he made the demon deal with Crowley?  Lots of little things made him and interesting and dynamic character even after his death.  I would certainly not classify him as a third wheel.

That said, I like Benny, and really hope they keep him around.  And I'm REALLY looking forward to Sam's vocal reaction to Dean's new buddy.  Dean killed Sam's friend last season because she was a monster and "would kill again."...now he's got a VAMPIRE buddy?  I don't think he should be a permanant addition to "Team Winchester", but he certainly does make for fun and interesting supporting cast.  I love Garth too.  Can't wait to see him this week again.

What I REALLY want is another episode with The Ghostfacers.  RUNNIN' INTO THE KITCHEN GETS HOT! GHOST! GHOSTFACERS!!!

Yeah well, Sam's monster friend did not help him survive a year in Purgatory.  I think that falls under 'extenuating circumstances' for Dean 100%.  I also really like the Benny character but he is obviously doomed from the start.  He is a sacraficial lamb for the Winchester war.

I also agree that they should do more Ghost Facers!  YEAH!!!!

And lastly I also miss Bobby a lot.  BOBBY!!!!  :(

 I don't know about Benny being an automatic expendable...I'm sure it's entirely possible, but on the other hand, Bobby was originally only going to be in the Season 1 finale, and look how long he ended up lasting.  If a character catches on, my bet is they'll keep him around.  I'm hoping that Benny's questions about his own existence and purpose is what makes him strong and interesting rather than being forboding of something bad and cliche to come.

sarcastic...well maybe third wheel was the wrong term to use.  Basically what I meant was is Benny going to replace Bobby in the boys monster hunting hijinks.

 I certainly hope so, tjanson ;) And axia, here's another reason I think Benny may stick around a while longer than you think - this show is not done by Joss Whedon.  They're not going to kill or severely change a character just because people start liking him...LOL