Michael Schwarz, AJAX MVP and creator of the WPF/E google group has posted about extending the SDK team's reflection article to include animations.  You can click the animated gif below to run the sample or check out the blog post for source code. 

My only comment on this sample, and it applies to the original, non-animated version as well, is that I'm not a fan of using scale transforms in reflection effects, it doesn't look natural to me, but to each his own.