Well, one Ottoman war over, and the next one is up for 1641...
The Shah is ending this war in a not-so advantageous position, but it could have been worse for him...though I suspect holding Damascus and Jerusalem is going to be difficult, at the end of such a long supply line, and ultimately not worth it.
On the other hand, the Latin Alliance and the Wittelsbach Emperor are going to be hammered. Outnumbered more than three-to-one in enemy territory, while they were already making a siege? This is a bad situation, no doubt about it.
Worse, even if they somehow manage to not get destroyed in the first day of battle, their supply lines are cut and Belgrade is besieged.
At some point it doesn't matter how good your Generals are if your troops have not the food and the water to fill their stomachs...
The word disaster comes to mind for what is certainly about to happen. There was already turnmoil and difficulties in the Holy Roman Empire, but if they really lose more than 61 000 men and lose all the gains of this campaigning season, the political arena is going to be ugly, very ugly. Constantinople will demand a return to the pre-war frontier at the very least, and I have a feeling the ransom one demands for an Emperor is not exactly small...