I've received so many inquiries and kudos about the Silverlight name, logo, and brand video internally and externally that I thought I'd post the real story of how it came together.

• Naming research was completed in Q3 2006.  We decided to hold it for a special event at a later date.  "WPF/E"- the codename of Silverlight was intentionally unappealing to keep mainstream consumers from installing it until we had good feedback from the developers/designers during the alpha (CTP) preview.
• Brand work was done by my team working with an outstanding design firm I'll mention here once I have clearance to do so (by them).  We kicked this off in October, and went through many iterations before landing on the animated logo and final frame lockup.  If you don't like the frame, you can blame me Long :)  The orb is a plasmic energy being held into shape by an unseen force, where it spins and flows, almost organically.
• The brand video was done by Phoenix Edit, a group of ex-Industrial Light & Magic wonks out of San Francisco.    The goal was to show many different Silverlight-enabled scenarios woven together – designer/developer collaboration, personalized e-commerce, devices, user-generated video, viral sharing, and the network effect on sales. We intentionally avoided excessive use of text or voiceover so the video will translate globally as we kick off events around the world. For the line, "Light up the Web" - you have me to blame.  It's more about illumination and blazing a trail vs. blazing anything else ;)
• The music in the brand video is by my friend and prominent UK DJ Andy Hunter. The song is “Go” off his album, “Exodus”.  Andy consulted on the project and the remix, and has considerable street cred touring with DJ Tiesto. His songs have been used in The Matrix games, and multiple movie/television show. Andy is now on Nettwerk records working on his next release.
• Customer and partner engagement was tightly synchronized.  During initial briefs, partners were shown a slide announcing the final name as "X-Plat Player Plug-in for Browsers" in Microsoft logotype, a self-deprecating way of noting that we knew the name had to be cool and were on the ball (ironically or sadly some thought that was the actual name!).  We'd show the logo without the name, and always used the name "WPF/E" in our discussions and external communications.
• For the press announce, named companies didn't even know the final name until a matter of hours before the release hit. We intentionally didn't publish any brand elements internally and had about a dozen people total that had access.  The product management team got really tired of hearing me talk about secrecy and except for a few small nits that went unnoticed, they really did us proud.

Some day I'll post the evolution timeline of the logo if others are interested.