On a wider political scale, there is a strong possibility of Italy looking to establish a Mediterranean pact (which might include France too, besides the usual suspects: ITTL France and Italy would have had friendly relations during WW2 - the more so if Italy becomes a co-belligerent in late 1943 or 1944 - as well as share common interests in the stability of Mediterranean). There might even be a common nuclear program in the cards.
Ooh! Could we perhaps see some co-operation between France/Italy in security operations in their North African colonies, a-la Portugal/Rhodesia/South Africa? Libya and Algeria's placement on the map would mean that cross-border operations, and shared intel, could allow both countries to cling on to their African provinces slightly longer ITTL.
I wonder what Greece's role would be in this, post-war. Would there still be Communist coup attempts there? Perhaps we might see Italy engage in peacekeeping operations in Greece and Yugoslavia, as a veil for asserting political and trade control over the Eastern Med. Without the fall of Fascism, but with growing Italian capitalism, and the general move away from overt imperialism, perhaps the Mare Nostrum doctrine would evolve, to better suit the modern day.