When I travelled last December, the food was the same compare to my previous trips. In terms of the seat, you'll get the same seat but with better recline, more legroom, and an improved audio system.
Word has it that WBC will get a dedicated purser in May, 2001. NWA said that they're going to make the service about the same as the old int'l FC. Hope that's true.
Do a search in CO's forum using the word "business first" to see what CO is like.
I myself am tempted to try CO's Business/First product the next time I travel to Asia in December but
a) I want to see the new terminal in Detroit
b) better scheduling to Asia