That is, don’t believe anything I say when you ask me about Silverlight vs. some other technology such as… well the one people keep asking about is Flash (or Flex).
1. Once a person has a stake in a product that person is physically incapable of having an objective opinion. In my experience that is a fact of life no matter how honest, reputable, sincere or incorruptible the person. Set aside cigarette scientists and those who work for (your pick: nuclear power companies, pharmaceuticals, etc. etc.) – when a company is feeding your children you cannot be objective about their product
2. There is more than one way to have a stake in a company, and perhaps the biggest is “sunk cost” and “cognitive dissonance” – in short, no one likes to (a) think they made the wrong choice (b) think the investment they’ve made in learning a technology may have been wasted or (c) wants to “start over.” So moving a .NET programmer from ASP.NET to Silverlight takes less force per unit of time than moving a Flash programmer.
3. There is no objective standpoint. No one is standing on a planetoid  objectively assessing Silverlight against any other product, nor could they. Every assessment you read, from within Microsoft, Adobe, or from the Media is written by a person who brings their  own history, agenda, bias, etc.
4. There are not objective criteria. Even if you could be objective, what criteria would you use? Each company has its own needs, not only for a specific project but also in terms of the staff and budget available. You don’t fight the next project with the team you want, you fight it with the team you have. Oops. A Rumsfield moment.
Okay, I’ll say this: I’m may not be the programmer I want to be, but I’m the only programmer I have, and I come to my work with two decades of experience, working in CPM, RSTS, DOS, Unix and then Windows since 1990 and .NET since 2000.
If I want to write an RIA, Silverlight is the natural fit; the fact that it is incredibly great, and that it is getting huge support from a very innovative group within an incredibly well funded company makes it a no-brainer – for me.
Topic for a different column: The three most encouraging events in the Dev-Div in the past decade are, in my opinion, the creation and release of Xaml, the hiring of Ray Ozzie and the promotion of ScottGu to VP; all of these signal an innovativeness that is almost shocking in an organization of this size.
My personal testimony to Silverlight is that after attending Mix07 I immediately incorporated Silverlight Consulting LLC in Massachusetts just long enough to be offered this job, for which I gave up 12 years as an independent. Silverlight is, in my eyes, the most exciting technology since .NET, possibly since Windows 3.1.
Since I’m not great at "my software is bigger than yours” I spend my time referring “is this the right technology for my company” questions and especially “how does this compare with ….” questions to others (who are better at it). But, understandably, the questions keep coming. So I tell my story of how and why I chose Silverlight and gently refer the questioner to those who have the comparative facts at their fingertips 
Then I try to focus on “how do I accomplish this in Silverlight” questions and, lately “what do I need to know, and why?” questions. I try to remember that I’m a developer, and to get better at writing code and at teaching and presenting and reminding folks not to believe anything I say.
 "No one is standing on a planetoid " — Saw a bumper-sticker: “Awww – Let Pluto be a planet.”
 "a person who brings their own history" We really need a gender neutral pronoun.
 " who have the comparative facts at their fingertips" Just because there is no objective standpoint and there are no objective criteria for all situations doesn’t mean that we don’t have objective comparative facts; I just don’t happen to know them.