Silverlight has been Microsoft's golden child since v2 was released last year. The impact within the community has been astounding. Some demand the use of Silverlight without actually recognizing when and where the technology makes sense and others scoff at Silverlight either in favor of Flash or as a technology as "useless" as Flash. I roll my eyes every time I hear any of these three opinions... and they happen a lot. Flash went thru the hype cycle years ago and now it's Silverlight's turn. What I find amusing is that the hype seems to be much more powerful with Silverlight than it ever was with Flash. All we can do is fight the good fight.
XAML is immensely powerful and will continue to grow as more and more WPF features make it into Silverlight. XAML takes a new way of thinking, but it's well worth it for the simplicity and ease of development you get. But, more important than XAML is the fact that you have any .NET language you want and, with the inclusion of the Dynamic Language Runtime (DLR), there's virtually no reason not to use Silverlight. The one and only benefit Flash has is more mature tools. This is very important, but it is only a matter of time. Microsoft has both the will and the ability to overcome the current Flash tooling. The days of Flash are severely numbered. A look at the job market only confirms this. I just wish I had some of the same numbers from when Flash was initially released to compare the difference.
I truly believe that, if you're a web developer using any language, you need to take the time to understand how Silverlight can benefit you. Yes, HTML5 is coming, but the power and flexibility of environments like Silverlight will quickly surpass anything the W3C will ever be able to come out with a specification for. Heck, in less than 2 years, we've seen 3 releases of Silverlight and a beta version for the fourth, with speculations that Silverlight 4 is likely to release at Mix 2010, making it 4 full releases in 2.5 years. I'd like to see any one W3C spec ratified and fully released in all major browsers in such a timeframe. Such a feat is completely unheard of. Nevertheless, don't let me blab on about it. The numbers speak for themselves...