As David states it's usual to find a film of oil coating the inside of the intercooler pipes, if you have only just noticed this then it could just be a buildup from over a decade on the road.
With the stock recirc valve it wouldn't be noticed as it heads back into the air feed to the turbo but as you have fitted an atmospheric dump valve it'll be more noticeable.
I'd clean out the pipes and intercooler best you can then top up your oil level. If you find the engine is using oil then you can start worrying about turbos, rings and all that hassle but my hope is the level doesn't change too much between service intervals mate.
(Remember that any oil leaks/weeps could mess with your oil level so rectify any you find)
Keep us posted buddy,
Jay