As per a training I just had with Elan, their new solution looks pretty nice. A lot of the same spec's as the other players but they use a controller that manages the video streams. Because of this, you only need a layer 3 switch and do not need a very expensive solution and the traffic doesn't effect your regular switch traffic. Plus their isn't VLAN tagging or any other complicated setup needed. Unfortunately, I think they are making a big mistake by making it proprietary to Elan.
Snap has a version on the horizon but I'm guessing qtr 1 of 18'.
"Just when I thought you couldn't possibly be any dumber, you go and do something like this... and totally redeem yourself!"