It's true, airplanes are not based, but crews are: and they can only be based where their assigned aircraft has at least a daily flight.
Varesino, intanto ben arrivato
: if by the new 747s you mean the 400ERFs and the 800s, they will all be freight aircraft and as far as europe is concerned will probably result in crews based in Manchester and Frankfurt (which for now are still -200 bases) in addition to Paris and London (which are already 400 bases). Pax 400 crews are already based in LHR, CDG and FRA.
Rome is currently a mixed destination, with the 747-400 pax coming to FCO part of the year and the A340 coming for the rest of the year, so there are no Rome based crews. However, word at FCO is that as of this summer or next summer at the latest, FCO will become a 747 destination only, thus opening the door to a Rome base (count me in
!!!) tax/onshore issues permitting.
Finally, judging by your nickname you will be happy to know CX is actively trying to open up MXP as a pax destination, and it is already "on the map" as a 400 freight destination... then again they've been talking about MXP for years...
MD