I've seen the 'tile' format on Win 7 phones and it's certainly different. AFAIK Win 8 UI looks very similar.
I'd be happy to try it, as soon as the devices start coming in at reasonable prices.
It's the added experience that'll make the difference, not just the look. If it looked like any other OS it may have few differentiating factors, and therefore be ignored. But is it to different?