Hell, Kankurou should've died from the bugs! They never even showed how he escaped Shino's bugs, he was just like "uh, here I am."

And I'd rather have Shino in the next arc than have him appear suddenly in this one. Kishimoto I think purposely had that whole "Shino is on a mission with his dad" thing so we wouldn't suspect him of coming. Besides, there already has been too many guest appearances.