Is iCloud utilizing Microsoft Azure and Amazon's cloud services?
infiniteapple.net
infiniteapple.net
There's a similar one here:
http://thenextweb.com/microsoft/2011/06/08/is-icloud-running...
I do find it interesting that internally developers were using AWS/Azure. Maybe they were doing it as a learning experience?
In any case, an interesting insight to Apple's internal developer culture. I'm pretty sure that Azure developers would get chided were they to ship code that communicated with AWS (and vice-versa).