You are correct we currently do not support testing of Flash objects. The closest we can come to meet your needs is an image verification. For example, if the player controls (play, pause, next, prev, etc.) are static and don't overlay the video, you could add an image verification of the player controls.
Another possible option would be to always pause the video at the exact same frame, then perform an image verification on what's displayed in the player window at that time. Unfortunately if you're off by one frame the image verification is likely to fail.
the Telerik team
for a live 'What's New in Test Studio R1 2011 SP2' event on Tuesday, July 19 at 2pm EST!
Have you looked at the new Online User Guide
for Telerik Test Studio?