Thanks to a new Microsoft (s MSFT) pilot program, Amazon Web Services’ (s AMZN) enterprise customers can now bring their EA Windows Server licenses into the cloud, activate them, and then launch Amazon EC2 instances running Microsoft Windows Server at the Linux/UNIX On-Demand or Reserved Instance prices. This is yet another step by Amazon to continuously woo the corporate customer and add features to meet the needs of large customers.

The Microsoft Pilot Program is only open to companies that are based (or have a legal entity) in the United States. The company must have an existing Microsoft Enterprise Agreement that does not expire within 12 months of your entry into the Pilot. In addition, Microsoft wants other assurances such as “licenses.” Enrollment starts today and will continue until September 23, 2010.