I have the same problem.
Anyone founds a solution to it?
This is a limitation of your browser not being able to display PDFs inline. However, I hope in the future to be able to remove the need for redirect, which only exists now because of a limitations in facelets with regards to binary data. It's unlikely I'll be able to get this in for 2.0.1, but I hope it doesn't take long.
Thanks again Norman,
Your are fast :-)
Put a hidden iframe on your page and target your PDF link to open in there. Works for me. You may have to do some browser detection as well to get cross browser coolness.