I've just reviewed the Silverlight showcase for the UK, an IT market I know pretty well, there are 31 apps featured and the break down looks like this
8 x Games = 26%,
6 x Experiments and fun = 19% - eg christmas cards and Xaml XEyes,
6 x Demos = 19% - eg a Deepzoom picture,
11 x Reasonable web sites = 36%
Realistically 31 apps for the whole of the UK, of which only around a third are real, is a tiny amount of development. This could indicate a couple of things,
1) Serious Silverlight development isn't happening in the UK, but maybe is elsewhere
2) Companies doing serious silverlight dev don't want to use Microsoft's showcase
3) There isn't much serious Silverlight development happening yet
My gut feel is that Silverlight is taking a while to become mainstream, it's a brilliant technology, but users don't buy technology or features, they buy benefits .... We need a couple of killer Silverlight apps, then it will take off like Ajax did, once google (and others) showed the way