In Norway there has been talk from the DMV equivalent [1] that people who don't have their cars updated in the recall will have their registrations cancelled. So if you keep driving, the police will stop you. Automated license plate scanners and all that, I don't think many will skip it.

What's more likely is that if many people feel their cars are sluggish after the update, aftermarket diesel tuning will become (even more) popular.

[1] Source (in Norwegian): http://www.vg.no/forbruker/bil-baat-og-motor/dieselskandalen...