Not that I have a particular beef with that, but as mentioned by Montfort in this thread, National will always be National, to some anyway.
The question is, who enforces this? Not so much for airports, but how about sports venues? For example, the Cap Center (actually, I think it was the Cap Centre) was always the Cap Center, and neither I nor my friends ever called it “US Air Arena.” Candlestick is still Candlestick to me, and not whatever it now is (is it 3Com?). Yet the sports announcers call these things by the sponsor’s name from day one.
Do the sponsors have something over local news outlets? I suppose they do with stations that have the contracts for the local teams, and I guess the teams could cut off contact with any stations that don’t jump on the bandwagon, but why would the local media and populace (as in Denver, for example) go along with a name change that’s nothing more than a sell-out to the highest bidder?