Passat is about the same weight at a CJAA Mk5/mk6, maybe 2-400LB heavier but it's not substantially heavier. They lightened the NMS by a crazy amount compared to previous gens.
It's hard to find solid weight information for a couple reasons. All the published numbers tend to be listed as 'base curb weight' numbers which leads me to believe that it doesn't account for subtle differences due to options...so what ever the base car would be with that engine and trans, but without accounting for much else.
I also tend to think that the supplied numbers are generic because perhaps the NHTSA or DOT wants a number so they can categorize cars for comparison, so it's in the best interest of VW for instance to provide the lowest viable number possible because someone may use that as a criteria for something...who knows.
At any rate this is a list of some weights that I found (again
base curb weight) provided via Edmunds under the specs. I have noticed that they do change from year to year however I still believe you want an accurate weight drive your car over a scale somewhere. My 1990 B3 TDI wagon 6MT weighed in a 3250 crossing the scale (me inside at ~200lbs + full tank and 100lbs of tools).
None of them are all that far apart, at least in the numbers reported by Edmunds. At any rate it would appear that the NMS did not actually lose a bunch of weight over the B6...and in fact may have actually gained some weight...if the numbers can be trusted.
Steve
2012 NMS 6MT TDI sedan 3360 lbs
2006 Mk5 Jetta TDI 5MT sedan 3197 lbs
2009 Mk6 Jetta TDI 6MT sedan 3230 lbs.
2005 B5.5 Passat TDI AT sedan 3450 lbs
2008 B6 Passat
6MT sedan 2.0t 3206 lbs
2008 B6 Passat DSG sedan 2.0t 3246 lbs
2007 B6 Passat DSG wagon 2.0t 3512 lbs
2008 B6 Passat DSG wagon 2.0t 3378 lbs
2009 B6 Passat DSG wagon 2.0t 3512 lbs
2010 B6 Passat DSG wagon 2.0t 3455 lbs.