Microsoft SilverLight XML vs. JSON

As many others, I am also excited about SilverLight.
So I downloaded the beta and took a look at some examples.

well, I know microsoft is going the XML way, but I was somewhat disappointed at it.
It is SO big...

After working with JSON (Javascript Object Notation) for quite a long time I feel that IMHO siverlight would be much better off using JSON and not XML.

How can you compete with flash when the download is SO big :(

What Do you think ?