This is a strange case. As I understand it, when the Euro was created Germany was concerned about handing over control of its money supply and as a result the treaty never overrode BBk's obligations in German law - the ECB sets policy but its implementation is down to the national central bank - therefore is odd that the ECJ is claiming that EU law is superior in this case.
It is likely that BBk will be able to convince the court that this action is appropriate and nothing will come of it but if cannot the program would continue and Germany would not be able to continue to take part.
On another note negotiations are set to continue next week but unless there is major movement I cannot see anything coming of them. However it is worth noting that we were in roughly the same position last year, with the WA negotiations deadlocked, and an agreement was found at the last minute.
Also, slightly related to Brexit - the Met. has dropped its investigation of Be Leave's founder, Darren Grimes.