The first plane isn't set to take off until maybe September of 2009. I think many of us would be hard pressed to make a suggestion as to which seat would be best.
If you're a >= 1P in status, then exit rows are always available and provide a great amount of space. My last flight on a 777 was in Y and I sat in what would be row 33 on the new (and old) config. Plenty of leg room, though I'd still suggest the aisle.