A quick check on airfleets.net for Northwest revealed to me that they now have 19 A330-300 and 11 A330-200 aircraft in their fleet.
I can't seem to come up with enough routes that all those 300's could be flying on . . .
From looking at the timetable I found out that at least there is
DTW-AMS 4 Daily on A330-300
DTW-CDG 1 Daily on A330-300
DTW-FRA 1 Daily on A330-300
DTW-LGW 1 Daily on A330-300
MSP-AMS 3 Daily on A330-300
MSP-LGW 1 Daily on A330-300
AMS-BOS 1 Daily on A330-300
But I still think I'm missing some, unless they have a lot of 300's sitting around as spares or use them on Pacific routes.
And if anyone knows what routes the 200's fly on, I know they do AMS - BOM/SEA/MEM and NRT - PDX/SEA. What are the others?