There's a chance that RAW is building towards a Jericho/Benoit showedown at SummerSlam so I'm thinking the best approach would be a quick heel turn.
Firstly, Jericho is currently a face yet from a storyline perspective it doesn't work out. Jericho was a top heel on RAW and turned only because of hooking up with Trish. Since she turned on him in return, there is no further reason why Jericho should continue on this path because we all know he's the arrogant a$$hole that bet a Canadian loony that he could sleep with her.
As for the subject of quick turns (many pointing to Goldberg's 6 week heel turn in WCW) never working out in the long run, one may look to Eddie Guerrero. For most of 2003, Los Guerrero's were a babyface tagteam. After Chavo got hurt, Tajiri replaced him and was eventually turned on. This heel turn lasted a month if I'm not mistaken since Eddie was still insanely over so the breif heel run was quickly forgotton.
A Jericho heel turn wouldn't work for just a short period of time, probably because he hasn't been a face for that long, but also because he has so many issues with heel Christian.
Also, Eddie Guerrero's heel turn was short because the fans rejected it and continued to cheer him. He did heelish things, but he lied, cheated and stole as a face, so he was never really a heel. Eventually the WWE decided to make him an official face again, because he was not working as a heel.
If Jericho was still a face against Benoit, it could work, but there aren't many face v face matchups so I would expect it to be a triple threat with someone like Kane, Christian or a returning HHH.
However, Jericho v Benoit is hardly set in stone, and I would not expect it to be the main event anyway.
maybe im mistaken but i seem to recall christian cutting a promo speaking about a world title challenge recently and then of corse jericho threw his name into the hat aswell. and given the jericho and christian feud not looking to be ending anytime soon. they may just be looking towards a triple threat with jericho christian and benoit and have an all canadian main event at summerslam.
however i would not like to see this, im sick to death of triple threats at the minute.