The codes represent the number of seats available in the various fare classes. P class is total first class seats available (9 = 9 or more), while F class is number of first class seats currently released for upgrades. If the P number is still big while the F number is zero, there's a good chance you'll get an upgrade, but it won't come until closer to flight time.

On a related note, has Northwest started releasing seats only right before the window is supposed to open? I've been watching a flight I'm scheduled to take on Wednesday (assuming the blizzard we're supposed to have in Denver doesn't cancel it), but the first class seats have been very slow to open. Prior to the platinum window, first class was completely open (16/16 seats), yet F was zeroed out. Prior to the gold window, 6 seats were released and were quickly claimed. Now typically silver upgrades around 5 or 6 PM the day before the window is supposed to open, but currently it's F9 P0 (First class currently has 7 seats assigned). It seems like they're trying to get around the EUA early upgrade "bug" by only releasing seats right before midnight.