It's going to be intereting if the Supreme Court rules that MS must hand over data protected by EU data protection laws when asked by the American Justice Department.
When some Microsoft employee in Ireland hands over data such data what's going to happen (a) to Microsoft Ireland and (b) to the employee and (c) to the MS Ireland Management that made it MS Ireland policy to  permit such handover.   I guess the answer to (a) is that Microsoft ireland will pay a massive fine; and the second time it happens the massive fine will really hurt.   The answer to (c) is a bit harder to guess - but again a large fine might be appropriate, or even a jail sentence (one can be pretty sure that if teh Supreme Court makes such a ruling the EU will harden up the regulations to make it painful to try to play games with them).  Of course if MS Ireland claims to have a firm policy not to hand over such data, any American senior management of MS Ireland had better avoid vacations in (or other visits to) the USA because they will be violating a ruling by the supreme court and failing to carry out their legal responsibilities imposed by a demand for the data by the Justice Department.  How (b) works out I haven't a clue, except that the employee concerned will have destroyed his reputation as someone who can be trusted with sensitive data, which makes him pretty well unemployable anywhere in the EU (and anywhere in any country with a decent view on data protection) unless he is qualified for jobs with no access to sensitive data.

We've already had a period where it was illegal for European companies to have sensitive data stored or processed in the USA (when the Safe Habor Agreement was declared void becuse the USA would not observe it).  I doubt the replacement agreement will survive very long, because it's extremely unlikely that the USA will observe that agreement any more than it did the last one, or that it will interpret the agreement as obliging only to pay lip service to the principles itis supposed to uphold.  I think a Supreme Court decision to back the justice department against Microsoft would ensure that data protection officials throughout the EU will watch very carefully to see if the there are viloations of the agreement - and it's very likely that the when the justice department demands data those officials will demand to see the evidence justifying the decision to demand seeing the data, since otherwise they would be trusting the same people whose failure to enforce the Safe Harbor Agreement lead to its being declared unreliable, not to be trusted, and hence void.

And Steve's "I'd just do it" attitude strikes me as something that may help ensure that the USA never gets decent data protection laws (because that attitude would render such laws unenforceable) and that would mean that the risk of having ever increasing trade barriers between the EU and the USA, including a total restriction on any sort of trade in IT services, would never go away.