Well, the essential thing to look at is that this is unlikely to alter the Soviet advance in the East. From this we therefore can say that it is unlikely that the Soviets will have a full occupation zone in Italy, as they reached Ljubljana 5 days after the Anglo-Americans reached Trieste IOTL, and even if the Allied advance in Italy is slowed, we can speculate on the opening of another front from France or some other such situation that would make up the difference.
However, I consider it likely that Rome gets split a la Berlin and Vienna, that Yugoslavia will get Trieste and that South Tyrol might be given back to the Austrians.
Perhaps something like this? US gets Sicily, the South and Lazio, France occupies South Tyrol (with mind that it gets added to Austria), Piedemont, Lombardy and Liguria, while Britain occupies Venezia, Tuscany, Romagna and a bit ot territory that ensures that the Swiss aren't completely surrounded by French occupied territory.