Azure was rolled out yesterday in China (June 6th) so I bet that's why the stock took off
People probably put 2+2 together and realized just how &*&%ing massive this is going to be.
"Microsoft is the first major U.S. provider to launch a public cloud in China. Windows Azure is rolling out in China through partner 21Vianet Group, a large carrier-neutral internet data services provider. Windows Azure service in China will be available on June 6."