I think everybody is being too optimistic over Shaun. Holmgren has no problem sitting his stars down. He has taken Alexander out of games they are winning during the 4th quarter - he doesn't mind playing Morris, who is a decent back.
The only game this season the Hawks "had in the bag" (I use that term loosely with the Hawks) was their first game vs. the 49ers. Alexander only got half the carries in that game: Game Stats ...although, he still managed three touchdowns!
No way I see Holmgren risk losing his star offensive player if they have the Division title wrapped up ~ especially with how sucky he has coached this season (he knows he hasn't done well with his talent). If the Jets win, which they definitely should, I say Morris and Strong get the load the entire second half. With the Falcons playing their starters in the beginning, Shaun gets 50-60 yards and a TD in one half: very mediocre day.
This is a tough call though.