Actually Zeus, you may want to know that Northwest is (and has been for awhile now) trying to finnagle a way to move its headquarters FROM Eagan, MN TO the Detroit Area. They haven't done so already because of some "deal" they made with the state of Minnesota that obligates NW to keep its headquarters there.
Northwest absolutely loves DTW. It brings in a lot of revenue with its very lucrative & high profile nonstop international routes such as NRT, KIX, PEK, SEL, LGW, MUC, CDG, AMS, etc., etc. Plus, all of that feed from the Midwest, upstate Michigan, the South, and southern Ontario does wonders to complement the 3+ million O & D population in the Detroit metro area. (And a lot of that population is quite affluent, especially from the northern suburbs).
--NW, pre-Sept 11, was even planning for its DTW-HKG nonstop. Who knows? They might wind up doing it anyway once the industry and the economy recovers.
In short, don't be surprised if a few years down the road Northwest will become just another company headquartered in Detroit. The airline and the Detroit/Wayne County/Michigan government have gotten verrrrry intimate over the years.
Don't worry. MSP will still play a major role in NW's hub & spoke operations even if it will no longer be NW's world headquarters.
One final word: You MSP'ers have always been spoiled with having TWO airlines simultaneously headquartered there... NW and North Central (later Republic) in the 60s, 70s, and 80s; and now NW and Sun Country! That's damn good for such a sleepy, severe wintry & super cold place like the Twin Cities!
P.S. I'm NOT from Detroit nor have ever been from there.