Well, I think BREXIT will come into play here. The EU has no authority over tax policy. This is specifically spelled out in the EU treaty. They do have anti-trust authority. So they are using anti-trust as a backdoor to control tax policy.
The high EU courts are going to decide whether or not anti-trust trumps sovereign tax authority. If so, I think there will be more countries leaving the EU. And there will certainly be more companies leaving the EU. I suspect they will go to England, or back to Bermuda.
It would be amusing....after BREXIT....that all of these US companies quietly relocate into the UK and set up a massive empire to avoid EU taxation. Just off jobs alone....you could be talking about 250,000 technology-related jobs across all of the EU in some flux and desperate to find a low-taxation location.