Hmmmm, looks like a 250/1 or something to me for the Wehrmacht as well as crew repairs or something and maybe my idea of advanced bunkers being a retreat point and having an a repair station upgrade, no idea.
As far as the Sherman Commander goes it has a weird shield emblem at the middle which reminds me of the All Units mod upgrade of giving tanks additional defense with an HP/Armor boost of some sort.
I mean there is little they can really do with the Sherman unless they introduce the Sherman Jumbo which I don't believe they will.
I am guessing that anything ranging from Sherman variations like the E8, 76(W), 105 and Flame Sherman are possible. Ability wise maybe they'll take ideas from the American Armored Company from CoH with raid tactics, the M8 Greyhound, War Machine and so on.
Edit: Looking at the Ost commander again it looks more and more like the Panzer Elite 250/10 Light AT Halftrack :
http://companyofheroes.wikia.com/wiki/Light_AT_Halftrack
But they did say no new models, maybe they're gonna port over the ones from CoH unless they are already hidden leftovers in the files like the emplacements and stuff, just give it a fresh coat of paint and voila.