Re: Once again - US cloud service. Two words from Europe.
You try it.
The PATRIOT Act empowers the security services to force Amazon* to provide the information they request (secretly - you'd never know about it). Wherever that information is held, and irrespective of any contract Amazon agreed to.
If Amazon don't comply - irrespective of why - it's serious jail time for the execs.
Hence no corporate lawyer would allow Amazon to operate such a setup.
That's the long and short of it (Microsoft admitted this http://www.zdnet.com/article/microsoft-admits-patriot-act-can-access-eu-based-cloud-data/ ) is that EU/Safe harbour is meaningless if Uncle Sam comes bounding over the horizon with a PATRIOT Act notice. Nothing has changed since then, so any EU firm trusting in safe harbour is playing with fire.
Incidentally, I was at an IBM get together before Xmas (they are a big supplier to us) and when our Information Security Officer explained that we wouldn't be interested in their *hosted* cloud offerings (no problem if we can host). From the response, this is a frequent occurrence, and over biscuits, we learned there was very high-level pressure going back to the US about it, since it was - demonstrably - costing dollars.