Silverlight was chosen, not because it means anything, but because it’s a lot easier to remember than the more cumbersome WPF/E. Simply stated, Silverlight is the extension of Windows Vista’s rich internet platform, Windows Presentation Foundation (WPF).

WPF is supposed to be Microsoft’s answer to Adobe’s Flex framework, both of which promise richer, more functional internet experiences than the more widely used Ajax style of programming. To drive the point home, WPF/E was Microsoft’s strategy to get as much of WPF as possible onto non-Microsoft platforms, like the Mac or the Firefox browser.

The unveiling of Silverlight is being made this week at the National Association of Broadcasters (NAB) conference in Las Vegas. And alongside the public rebranding, Microsoft announced it has a few early takers of the format. They include Major League Baseball and Brightcove, an Internet TV startup founded by ColdFusion inventor Jeremy Allaire.

At the upcoming Microsoft MIX conference, Microsoft will announce new developer tooling for Silverlight.

When Microsoft first announced what is now Silverlight last fall, it promised release in the first half of the year. Microsoft released a Community Technology Preview back in February, and claims it will make its promises for getting it out the door no later than June.