Today at the World Partner Conference in New Orleans, we announced the business model for the Azure Services Platform, and opened up free testing for everyone. Windows Azure, SQL Azure and .NET Services will be commercially available at the Professional Developer Conference 2009 (November), in the meantime developers can test the CTP as from today at no cost.
Check out the Windows Azure blog post for the full details.
You might also have seen the announcement of name this name change. CTP is expected in August 2009. Follow the official blog for more details.
Visit the Azure Services Portal to get started: http://www.azure.com/.