How big enterprises are moving towards Public Cloud? Could someone please share any case study.

I think you could find some in Amazon AWS site, promoting their service :

http://aws.amazon.com/solutions/case-studies/smugmug/

This are case study that I could find :

http://arxiv.org/ftp/arxiv/papers/1002/1002.3492.pdf

http://www.cisco.com/web/services/it-case-studies/freeport-mcmoran-virtual-data-center-case-study.html

http://www.cisco.com/web/services/it-case-studies/docs/freeport-mcmoran-virtual-data-center-case-study.pdf

Thanks Clarence for this update. Really appreciate. I should change my question to ask "How big enterprises (specific to Gulf companies) are migrating their workload in Public Cloud?

I will post another question for that so that we can understand how those enterprises are accepting Public Cloud (IaaS).

Best Regards

Go for Microsoft cloud service, office365 for AD/Exchange and Azure for hosting different solution.