Are the first 4 A350s due in 2015? They may have cause to hold on to a few 330s when they have all 9 350s, the newest 3 330s arrived in 2008 IIRC? So they would be roughly ten years old when all the 350s are here. LAX is 15 years old now (and showing it from what I hear)
They have being delayed and the first will be in 2018 with all 9 in service by 2020.
There will more than likely be also a new A330 destination in FL either Ft. Lauderdale or Miami.
Personally hope for Ft. Lauderdale over Miami.