I think Jericho won't necessarily need a storyline upon his return. I see him coming in sort of as a shade of gray type character, not necessarily a face, but not necessarily a heel, either. My guess is the night after Survivor Series, Raw will continually be interrupted by the SAVE_US promos until the second hour, when someone comes out to cut a promo, cuing the return of Jericho.
Waiting for him to debut after Survivor Series is honestly a smart move on the WWE's part. They're going to let the current rivalries and stories come to their big conclusion at SS. Typically after a big ppv, the WWE likes to wipe the slate clean and start new angles and stories. Jericho's debut would be the biggest new angle they can have going. Odds are they will find a way to work him back. My money remains on him returning opposing Kennedy. He can win the IC belt the night before, come out on Raw and talk about how he will undoubtedly be the greatest IC champ of all time and how he will bring new life to the WWE. Cue a Save_Us promo on the 'tron, and BAM! Jericho is back. Instant, semi-logical feud, especially considering Jericho is one of the greatest IC champs ever. It would work two-fold, as it would not only re-introduce Jericho, but also help Kennedy become a bigger player in the grand scheme of the WWE.
Another scenario is to have Jericho come out and feud with Umaga, as the HHH/Umaga feud is sort of stale at this point.
I dunno...go jericho, go! go jericho, go!