Microsoft now has more than 10,000 customers (each with an unspecified number of users) using its Windows Azure cloud environment.

That new milestone was mentioned by Doug Hauger, General Manager of Windows Azure, during his appearance on June 3 at the Cowen & Co. Tech Conference. (I listened to him via the Webcast.)

Hauger shared some other new data and statistics. There are four main workloads customers are running on Windows Azure — Microsoft’s cloud operating environment which became commercially available in February this year. The four: On/off batch job computing; quick start-up (with no need or money to build out a private data center; unpredictable bursting; and predictable bursting.