Let me elaborate further about the utilization of the 762s. During summer 2007, at each night (say midnight EDT), the planes will be at:

5 planes flying from EWR to GRU, DUB, ZRH, FCO & MXP (ATH replacing MXP after 6/7)
1 plane GRU to EWR
1 plane either flying EWR to CDG, or IAH to AMS
1 plane IAH to EZE
1 plane EZE to IAH
1 plane overnight at IAH

Because there's often a spare 764 at EWR but no spare 762, you sometimes see either the ZRH or MXP substituted by the 764.