What you can or can't view on the device browser depends a whole lot on what the page does and how it does it. Keep in mind that the browser is not as full-featured as a desktop browser and that OS is not the same as a desktop OS.
With that in mind, you can then look at what your page requires. For silverlight, the client needs Silverlight runtimes (you install those on your desktop, right)? There is no Silverlight client for Windows CE, so that means that it can't meet the requirements to view a Silverlight application.
For general ASP.NET (and really any other web technology) it depends. Do your pages use server-side controls to eventually emit basic HTML and Javascript to the client? If so, then there's a strong possibility it will work just fine. Do your pages require client side controls (Flash, ActiveX objects, etc)? Unless you have those controls for the client OS and processor, then those won't work either.
And after all of that, you also have to bear in mind that Windows CE is a modular OS, so it may or may not have a browser. Even if it does, it may or may not have scripting support. It all depends on what was baked into the OS from the OEM.
So the way to truly know if it will work is to try it.