I would find Xavi more useful than Trezeguet for Juventus in a renewed squad next season, counting an arrival of a new forward and two defenders. We would not need additional purchases for the midfield.
And yes, I would love to see Maresca - Xavi play in the midfield.
Moggi might as well look into this, because Barcelona has been making inquiries about Trezeguet, so theoretically we could exchange them (with Barca adding some cash of course). Cause if a new forward does indeed arrive in the summer, this should geopardize Trezeguet's playing time, considering that Del Piero, Di Vaio and Micolli stay.
But as you guys mentioned, if one plays in Spain, it's difficult to play in Italy. Rivaldo is the most recent case.