I have mixed feelings. The Metro UI described one specific portion of the Windows 8 interface, which gives it a use for differentiating between metro-style and old-windows-style. It seemed like good branding. And, one that could be shared across platforms.

Now it's "Window 8 Phone featuring Windows 8-style UI" where the unique Metro branding could have served well.

Then again, I noticed a friend had Windows 8 loaded on his laptop the other day, and he had no idea what I was talking about when I asked how "metro" was