According to WinRumors Microsoft is going to announce the availability of Silverlight for Xbox at Mix. For developers this would be great because with some resizing, etc they can take their Silverlight apps and sell them on a bigger screen. And obviously as the Microsoft ecosystem expands there’s more of an incentive to make apps for it (for both Windows Phones and Xbox and in time PC which you can do now just not through a Marketplace). Of course if they time them in so you can buy once and use them in both places I think everyone would benefit (as users would be more likely to pay for an app that has the additional use).
If you think you’ve heard this already you’re not mistaken. About 2 years ago Microsoft said that they were going to make Silverlight available on the Xbox 360. Let’s hope that if the new rumor pans out that the release is immediate and we’re not an another 2 year cycle.