Check out this post on JavaFX, it is pretty good short article about JavaFX and how it compares to Silverlight.

However, I do think that Silverlight has the momentum and since it will work in the Compact CE O/S, which even though Google is talking about how their phone is a "clean" O/S, Compact CE has a much better audience and "eyeballs".  Having Silverlight run on the CE based phones like the Smartphone and PocketPC phones is going to be attractive to developers.

Having competition like Google will likely help Microsoft to define their product offering, Windows CE has been a superior product for it's entire life and that will continue.