I just noticed on the Microsoft Expression site that the RC is available.
Downloading it now and will test it soon.

Download Expression Blend RC

Maybe you have read and seen this fascinating video and thought, "Hmm... I want to do this myself".

Well, now you can.

Alessandro masserdotti from Tinker.it has posted his instructions on how to build the "Multitouch table".
Using Plexiglas, LED's and what not, they recreated this technique.

So, follow his instructions and try it for yourself!