MSN Soap BOX

Today i was looking at the video sample on Microsoft MSN web site
and i look at the source of the html page playing the page.
My surprise was that the page is working in both IE7 and Firefox Mozilla.
When i look at the source you can see a weird
block with a reference to a VideoService.asmx. and then
an other blog with a very strange HTML tag

tp="Msn.Controls.Mediaplayer"

So what is this mysterious Msn.Controls.Mediaplayer.

text/xmlScript
http://www.nikhilk.net/AtlasXMLScript.aspx

and what is returned by the asmx js method
http://soapbox.msn.com/services/VideoService.asmx/js

.....