My '01 Golf TDI had a few issues, but mostly relating back to me driving it into the ocean and getting it stuck in the sand at Daytona Beach (long, stupid, sad story). Really, it just needed a few non-maintenance items thru 302K, and my friend saw the car being driven this past year still! Bad then, the quality of diesel fuel in North America varied widely and was high sulphur which didn't help, so if drivers used crappy fuel I would imagine they'd have problems after awhile.
'07 Golf GTI was problem-free thru 32K, and I've got over 10K on my '10 Golf TDI Wagen with nothing yet (should hope not!). I'll be putting 70K+ a year on 'er and plan to keep it over 300K... so I'll be disclosing any issues encountered along the way. Love the car and don't have desire or envy to drive anything else right now.