I also would love to see UA dump there 737 and 757 fleet and replace them with A320s and A321s, respectively. The only good thing about the 757 to me is 24 F seats because I cannot stand Boeing's idea of narrowbody Economy. I am quite comfy in Airbus', however, so don't fear - you won't be fighting me for an upgrade seat.

I also cannot see any US airline buying the A380. The two reasons you buy an A380 do not apply to any US airline. Hell, if anyone buys it first, it will be B6 who will run it in a 1000-pax all-Economy config between JFK and LHR.

Not sure why UA went with Airbus for their single-aisle purchase, but they won't choose them for dual-aisle. So no A330s or A340s. It will be the 777 and, down the road, the 7E7. But the 763 has a lot of life in them, so it will probably be 2010-2015 before they commit.

777-200LRs will probably not be an option, since it only makes sense for LAX/SFO-SYD and the 774 seems to be a better fit. The 777-300ER is a possibility, but it looks like UA is in the business of shrinking their international routes, not expanding them, and 777-200ERs handle all their current traffic.