Well, the first thing you'd see is Eastern Europe being deprived of a financial center; I presume in a world in which Venice isen't independent and we're still seeing Napoleon fall the region would be annexed either into Lombardy or perhaps Austria. Without the pro-industrial and pro-banking laws of the state, I can't imagine the attraction/generation of as much capital under the reactionary regimes of post-Napoleonic Italy or Metternich's Vienna, so you'd see alot less industrial/infrastructural development in the Ottoman Balkans; Bosnia and Albania in particular, and Lombardy (Vienna is probably a wash; its hard to say if having access to the world markets via a decent port would make up for their limited access to capital in terms of allowing Upper Austria, Tyrol's, and Slavonia's moderate industrial development IRL. Any development that did happen would probably be more politically motivated than purely economical though). This would result, in the long run, in a weaker, more agricultural Ottomans and less urbanization in the centeral Italian states, as well as perhaps a politically-stronger Hapsburgs. We may even see the Turks get beaten on enough to lose their control of the Balkans before Islamization sets in, allowing for the formation of Orthodox states beyond Romania to form and Russia to expand its influence enough to avoid its economic collapse and the Eastern Crisis.
Secondly, Italian Pan-Nationalism might have been able to survive its post-Napoleonic drop in popularity, since it woulden't be totally associated with French influence as it is in our timeline (The fact that Paris was always funding those Pan-Nationalists diden't help). The Papal States and Two Sicilies might have been strong enough to survive, but I imagine Sardinia, Piedmont, Genoa, Lombardy, Lucca, Venice (If not under Austria), and Modenia would have at least Federated, rather than remaining in the weak "firm league of friendship" of the Not Roman, Not Holy, Not Confederation. How an Italy would have affected the European Balance of Power depends alot on its size and butterflies though, as well as how strong its level of political unity is.