Since I'm in the Netherlands now, I decided to send out an email to find out more about Superchips Bluefin. The word from the local tuner guys in Amsterdam (Superchips dealer) is that from 2009 onwards, BMW changed the software on the ECUs for the 320d which doesn't allow plug and play tuning anymore. While you can still send in your ECU for reprogramming and get Superchips performance, it can only be done at a dealer and not plug and play with Bluefin.
So in short even if you wanted to chip your diesel, at least right now, you can't do it easily. Note though this is different from what the Bluefin.co.uk website says, so I'm still waiting for email from the other tuner guys a bit further away.