UAL's Pacific operations would be split up, no way the DOJ would allow NWA to "own" NRT.
UAL has three main gateways to Asia/Pacific:
SFO, LAX and Narita.
Since NWA already has a hub in Narita exclude them, since the Narita hub and it's beyond rights are very valuable expect a bidding war between AA and DL.
I could see a CO hub in LAX, something along the lines of EWR. International flights to NRT, KIX, SYD,Auckland, Melbourne, Hong Kong, Guam, Guatemala City, San Salvador, San Jose, Mexico City, and London.
Since NWA is a major Pratt and Whitney customer NWA picking up a number of UAL's P&W powered 777s to expand from SFO and replace older 747-200s makes sense (to me atleast).
Also DL might be interested in some UAL 777s since they too are a big P&W customer (although the few 777s they did order were Trent powered).
Eastern Air lines flt # 701, EWR-MCO Boeing 757