Silverlight Game Engine?

Every once in awhile I look around for a Silverlight Game Engine.  When I do a search and I get the Popfly Game Engine toward the top of the search return, it shows that there isn’t much activity.  Why?  Popfly is dead.  The engine could be useful but it isn’t really functional.  It appears that the Balder engine and to a lesser extent the Farseer Physics Engine are the two that are the strongest ones.

Unfortunate after all Silverlight really needs a good game engine, a free game engine.  Mainly because I am too lazy to build one.  And too cheap to purchase SunBurn.

I have reviewed the ones on Codeplex, and with the exception of FarSeer Physics engine, the other engines like Balder seem to have moved off into other directions.

Boo.

What would a game engine for students and professor look like?