The EU needs to give a deadline by which the existing SH will be dead unless there is a major change in US legislation - one which will be binding on the NSA with a treaty binding the US govt.
No more NSLs.
No more rubber stamping courts.
No more DoJ fishing expeditions.
The whole lot repealed from US law.
The deadline should be just sufficient for companies to bring their data home with a modicum of panic if they get their backsides into action PDQ; sufficient panic to give them serious worries about ever getting into that situation again.
Then let's see how fast US officialdom can reform to try to meet the deadline from their side. It would help if there were increased political pressures in the US. Isn't there an election coming up soon?