Emirates to Denver? ... Denver International Airport is a big connection hub, so I doubt Emirates will fly over here.
This doesn't make any sense whatsoever. Every city Emirates flies to in the USA is a large connection point: SEA, SFO, LAX, IAH, DFW, JFK, and (coming soon) IAD.
As we all know, UAE203/204 will be upgraded to an A380 by the end of this year or beginning of next, and UAE225/226 will be upgraded to an A380 by January 2013. Also, the newest Emirates route will be to IAD starting September 12, 2012 operating with a Boeing 777-300ER.
Generalization. Not everyone knows that the flights will be upgraded.
Portland, OR? <------ Unlikely
The next city for Emirates, according to their website, is Washington, DC.