I wouldn't be too concerned, it's quite normal for JTD's.
If you take the engine cover off, there's a crankcase breather pipe at the front of rocker box which goes into the air intake ducting before the turbo, the oil vapour from this condenses out in the intercooler.
If it's a few drips then no problem, if you think that's bad take a look at the inside of the inlet manifold, it'll make you weep!