Goes into stock week 38 (2 weeks from now) and I think that I'll probably get it a week after that. So in about 3 weeks.
But your dealer should be able to tell you when the new iDrive is being fitted (I assume that you mean the new iDrive software). Last reports said week 36 build (last week) in the UK.
If you are looking at it, I also heard that the new multifunctional information display and HUD are now available together from week 36 build.
F10 530d SE. Imperial Blue Xirallic. Venetian Beige. Adaptive Drive and lots of toys!