Prussias not going to lose Rhineland-Westphalia unless it suffers a ridicolous decisive defeat - which wont happen. Rhineland-Westphalia really is "all or nothing" - if Prussia loses it it has lost its great power status. I mean, Im sure Austria would like that, but it wouldnt be worth the additional expenses and risks of an enlengthened war.
I think everything has been said here: Austria will regain Silesia, Saxony will regain the pre-1815 borders (which excluded Halle, btw, heh), Schleswig-Holstein will become independent... Bavaria will take some lands at the Palatinatian-Rhinelandish border, with some luck for them even the entire Trier-Koblenz region, Hannover might nibble a bit at Westphalia and Prov. Saxony, Hesse-Kassel might gain some of Prussias Thuringian possessions, Nassau might regain Siegen, Hesse-Darmstadt might regain parts or maybe all of the former Duchy of Westphalia, and Württemberg and Baden will probably divide the Province of Hohenzollern between them.