scan.co.uk had a demo day and it does look very very impressive and from what they where saying its not just over wifi you can stream games from you PC to anywhere aslong as you have a internet connection (though ping could be an issue over some connections) im still on the google nexus 7 2012 which has the predecessor chip to the Shield. but yes the shield is very very good a bit pricy but still impressive and you can use mini hdmi to connect it to a big screen
im not really an nvidia fan always prefer AMD but what theyve done with the shield deserves respect and i do intend to get one at some point