Austria and France were enemies, France and the Turk allies working to the same ends (much like England and Russia against Germany in both Wars). Protestants were more concerned with defending their own christian freedom from the Catholic powers than that of other christians. So don't expect England and Sweden and north Germany to march off to attack the infidel, rather to weaken France and Spain (the old English bogeys) or reduce Poland-Lithuania, Austria and Bavaria, presently threatened by the Turk. As has been stated, even if Vienna falls, who can conceive of the Turk moving much farther - he hasn't advanced much since 1550 - and only then will a Protestant League consider defending each other but even this is unlikely. Unlike Central Europe, Germany (and Italy) are densely populated, broken by rivers, woods and mountains.
Even if the Turks are not thrown back within two years, it will take a decade or two to digest Austria, Bohemia, Poland-Lithuania and Venice - assuming it's even possible for the Turk to do with the aid of France, Brandenburg and Sweden - and I think not. Once contiguous borders are created along the Danube in Bavaria and across Silesia and Poland, then and only then will the German and Scandinavians united against the Turk, at which point the hollow balloon will collapse and Bosnia be re-established in Thrace and Macedonia. That is, Calvinist Hungary will be freed (with her medieval adjuncts Transylvania, Croatia, Bosnia and what is now north Serbia) and a flood of moslem colonists will be pressed back to a line running east-west from the Black Sea to the Adriatic about where Albania is.
The Turks will be stronger for it, the French will have their Rhine border and probably Baden, Westphalia and the Austrian Netherlands. Prussia and Bavaria will contest primacy in Germany, but Bavaria though Emperor will be devastated and gained little territorially except maybe Tirol and some Italian towns. Brandenburg-Prussia will become a Kingdom as the Imperial dignity is weakened, strengthened by conquest in Lithuania, west Poland, Silesia, Saxony and various other territories, also perhaps Franconia (The Brandenburgers held Hof I believe in what is now north Bavaria). Sweden will have gained territory in Livonia and parts of Lithuanian Ruthenia (Belarus). Other than that, a Vasa on the throne? The question then becomes whether Sweden is weakened enough that it loses it all to Russia.
Bohemia and Great Hungary become question marks.
Liberated by an alliance of powers, they become pawns in a struggle for influence. Bohemia may be given to the Wettins in exchange for Saxony, or given to the Dukes of Brunswick (as heirs of a sort to the Winter King's wife Elizabeth Stuart) in exchange likewise for 'Hanover'. If the French want to or have the power, maybe James III of England becomes King. I suspect that Brandenburg either takes it outright and outflanks Saxony, or takes Saxony in exchange.
Still, at the end of the day, it has to be said that the chances were small that the Turks could have held the city for any serious length of time given the need to crush a relief army (thus setting up the destruction of their enemies) and then the need to overrun densely populated areas of defensive terrain at the end of a long supply chain.