Depends on what sort of app is required doesn't it.
Choice of interface is much more likely to constrain requirements than enable them.
It's this sort of thinking that got us into the client side executable versus RIA drivel.
Even if there was a real desire for a metro interface and it was suitable, we've still got to support older versions of windows, so any Metro stuff would have to be an optional extra for 8ers. Well we'd like to sell you our software but first you are going to have to upgrade your entire infrastructure is going to make us look like clueless propeller heads or Gartner types isn't it...

No suitable voting option, so didn't...