Let's face it, in MSDN documentation there is often a very constrainted information about development tools, often to the point of being unusable. But there are many ways to get around that, one way, read blogs, not just this one.
For example you might type in “Video Class XNA” into my search engine and end up with the following, which for Windows Phone would be useless, but if I am switching to Windows Phone 7, I might know that XNA is used on the XBox and Windows. In this case the search result is useless, I needed to look for the MediaPlayer. Here is what you would get from that search, and you might miss that it isn't for use with Windows Phone 7.
The Video Class is not the one you use in WP7!
Use MediaPlayerLauncher class
What I needed was the following, although the article isn't terribly useful, it does gets you on the right track. Now, the question is this: Why didn’t the Video Class point out that for Windows Phone 7, the recommend class for playing a video is MediaPlayerLauncher Class?
Just wondering, or the community (or even me) could suggest it right? Nope, get the “Unable to Service request” page. Anyway, make sure to go to the link below for the equivalent (that is: not very useful, except it shows that you need reference the Microsoft.Phone.Tasks dll).
That’s it for today. Keep at it, Windows Phone 7 is very worthwhile!