Microsoft recently announced "Silverlight" which it says "is a cross-browser, cross-platform plug-in for delivering the next generation of Microsoft .NET–based media experiences and rich interactive applications for the Web."

1.37MB installer installed seamlesly in my Vista and woks fine in my Firefox too.

My experience with "Expression Studio" was not really a good one(with a lot of bugs in it) I think silverlight lacks a punch which Flash delivers in terms of graphics and interactivity.

The only one feature I liked in "Silverlight" was 3D transformation of bitmap images, but tools like "Papervision 3D" for Flash will definitely fill this vacuum.

They also have a new site http://www.tafiti.com/ similar to Live.com or msn search which uses "Silverlight" to interactively deliver search results. Doesn't seem to be quick and as compelling as Flash.