What the Hell can .Net do exactly?

What's an example of a possible application that can be made with .Net?

What's a current example of an application using .Net?

I was trying to find a program that could make a jpg thumbnail of flash movies the other day (for a server, so anything with a GUI is out).  Apparently the only way this has been done so far is on .NET (create flash player OCX control on server, programmatically capture jpg of control). 

So in terms of supporting proprietary web crap like flash, .NET is apparently a step ahead of Linux for what it's worth.