Silverlight for WP only - 没有跨域调用限制

Silverlight for Destkop 如有cross-domain调用，则需要被调用方提供一个policy文件。

Silverlight for Windows Phone 去掉了这个限制 - 来自wp论坛的信息

It was explicitly stated in one of the sessions (I'm sorry I can't remember which one) that cross-domain restrictions don't apply to WP7S (otherwise you've be very limited in the sites you could connect to, since it would be only those with the file explicitly allowing cross-domain access, given that the app itself has no originating web domain).