In the past I invested time in learning how to develop with Silverlight. I stopped when it became clear  MS was going to scrap it. They pulled The Gu away from it, Jesse the Silverlight Geek stopped working for Microsoft, and it seemed like Ballmer's "Developer's, developer's, developer's" rant was just more lip service. Microsoft develops something, promotes it to developers, then walks away and pushes the next something to replace the last something; leaving the many who invest time, effort, and money chasing Microsoft technology royally screwed.

Microsoft killed off Silverlight.net this week. The Silverlight gallery is gone along with the Silverlight blogs, and 90% of the video training series as Microsoft prepares to kill off Siverlight.

From the comments:

The biggest mistake Microsoft made was to stop developing VB6. Everything after that has been a failure.

I agree that Microsoft stopping development of VB6 was a huge mistake.