Hey Matt, sorry to say there is no update, as the part hasn't arrived yet. Hopefully it should be in some time this week. I'll give the dealer a call for an update.
I am not too concerned about it atm, in that they have at least identified a problem, and they would have kept the car if they deemed it was serious enough. And if it does cause damage to other components like the suspension, then they have it on record that it has been in for the knock problem. It probably sounds worse than it is, as my passengers can't hear it. The most annoying bit is seeing a bump in the road and the anticipation of the knock, and feeling it in the steering.
Unfortunately, there are always going to issues with a new model for any manufacturer, and that's one of the risks that us early buyers are going to have to accept. But yeah, it does suck when you pay lots of $$ for a car with a problem. The best we can hope for, is that BMW come up with a permanent fix. The steering wheel vibration issue has been going on for ages, so there may not be a magic quick fix for our issue for some time.