There will be some bickering over which of the Crusade participants gets what, but it's possible to guess an outline.
The Byzantine Empire regains central Greece and most of Thrace. If they're really lucky they might get Thessaloniki.
The crusading army resurrects Bulgaria as a kingdom under John Hunyadi.
Serbia restores its pre-war territories and expands slightly to the south and east.
Venice regains some ports in the Aegean and Greece. Most importantly, the Venetians might get the city of Thessaloniki, and maybe even Gallipoli.
The city-state of Ragusa starts off a tiny merchant Empire by acquiring one or two ports in Albania.
Alphonso V of Aragon and Sicily acquires several vassals across the Balkans and may become a major power in the region in the next few decades.
The Ottomans survive in Anatolia, but many of their neighbors, such as the Karamanids, will have taken advantage of the Ottoman debacle to attack and seize border regions.