I'd think at this point, it would be smart for the Blues to then trade Allen to Dallas or Calgary and get a forward or two in return, if a Bishop-Shattenkirk swap were to go down in the first place.

I think the Blues are stuck with Allen. I have a lot more confidence in him as a platoon goalie, where he's posted much better numbers. I think Allen would, in this scenario, get dealt when Husso steps up to the plate. Allen will probably warrant a decent player but there's no reason, in my opinion, to force a move on him when his value's at its worst.