Bernie 2012,
The reason why I won't consider the A350 is 2 fold. First, its release is years away and we would likely not be able to receive this a/c until years after that. Second, I am reluctant to acquire brand new a/c from manufacturers because of the notorious kinks you would have to deal with such as the recent 787 battery fiasco and A380's cracked wings, to name a few.
In addition, the acquisition (purchase or lease rates) for new model a/c is significantly higher than for older ones. Given that the A330 is approaching the end of its manufacturing life-cycle, Airbus would be eager to sell a few more at steep discounts. The A330 would generate higher yields for LY than the 767 and 777 fleets combined currently do.
As far as flying to SYD, I would not be interested in that route for several reasons. First, I don't believe traffic numbers between Australia and Israel are high enough to justify the expense of opening up this relatively ULH route (please don't quote me on that as I do not have the actual figures) and LY's current code share agreement with QF from BKK works well. Second, the Australian government has, in the past, refused to allow EL AL security to carry weapons on their soil which would pose a security problem.