If it has been pi$$ing it down, then condensation is common.
However, you need to be slightly particular on how you are defining condenstion with the headlamps. If it is similar to the "fog" you get when breathing on a cold mirror, then this is perfectly OK, and will be rejected for any warranty claim. But if you can visibly see individual water droplets - say about 2-3mm in diameter, then this is cause for warranty - but you will have to be "pushy" when trying to claim.
An "industry" guideline for checking headlamp misting - on a dry day, with a stationary car, turn on the headlamps and leave them for 10-15 minutes. The "fog" should clear (or been seen to be reducing), but if there is no change, or if water droplets still remain, then that is grounds for a valid warranty claim. Unfortunatly, some VW stealers try to deny knowing about this, even though there is a very clear TSB from Volkswagen AG confirming this very test!
HTH