Microsoft is all out to let you try out the Metro UI. Instead of physically passing you a phone, Microsoft has done a Windows Phone Simulator using HTML5. It is simple way to let people try out the UI.
I have tried it on iOS. It is not the real thing but enough for you to know a little more on the Metro UI concept. To access this demo, you will need iOS or Android devices. Click the below link to access the demo. Have fun.