I just don't think it's clever to sell two forwards mid season. Bad move IMO. If Vucinic was staying on, it was cool. Now that he isn't, it would make sense for Quag to remain as part of the squad. He is a fairly dependable player to have around.
As for the news, dunno how reliable mediaset is, but GDM said, that Lazio want Postiga coz his buying terms are more acceptable and Juve wanted to exchange Quag and Gabba, and Samp refused. He said another likely destination is England. Followed by Bozzo coming out and saying thatnQuag is going to be staying at Juve and Juve are keeping him till end of season at least.