On Twitter I’ve found a very interesting story: Apples iCloud is using Windows Azure and Amazon AWS. A iOS5 Beta User was able to tape-record the Traffic with the help of a Proxy while he was sending a picture on a iMessage service. Amazon AWS and the Blob Storage of Windows Azure were named as data source for up- and download. (Here you can see a screenshot from the Sniffers)
It’s not clear if the usage was only temporary (in fact Apple has built his own huge data center) or if the files lay there only as a cache and Amazon and Azure only worked as CDN.
Kind of ironical that Apple is using Microsoft services but on the other hand it’s a great opportunity and reference for the Windows Azure Team. Same thing for Amazon.