Silverlight with ado.net DataServices

Does anyone have a good and clear article about why silverlight 开发者_开发知识库requires a callback everytime when I make a data access attempt?

This is a fairly straightforward and plain explanation of why MS chose to keep virtually all external requests asynchronus:

http://petesbloggerama.blogspot.com/2008/07/omg-silverlight-asynchronous-is-evil.html