Well at the moment no one knows what's next. Maybe nothing falls, still, no one knows.
The FAQs being setup answer all except, what's next and what to do:
Frequently Asked Questions on the Judgment of the CJEU on the US/EU Safe Harbor Program | Global Compliance News
Some companies like box.com will open an EU subsidiary with EU hosted datacenter for EU customer's data to keep within EU, simply they no more export to USA, it should solve the issue:
Box to open European data centres after ECJ ruling on Safe Harbor - Business Insider