I suspect the answer is yes, you can embed a Silverlight applet in a JSP, but I'm having a very difficult time finding any examples of this. Seems to me that I can just use the HTML that would go in a strict HTML file...
<object width="300" height="300"
data="data:application/x-silverlight-2,"
type="application/x-silverlight-2" >
<param name="source" value="SomeSilverlightApplet.xap"/>
</object>
... and it would just work.
I would test this, but finding a .xap file that I can download and test with is more difficult than I would like. Perhaps it is just because a Java programmer like myself doesn't know where to look.