[Aethaeryn]

  > White on solid color is what basic metro tiles look like, though, and
  > the offenders are the parties who shove their faux-3D logo into the
  > tile without adapting it to the platform.

Why didn't Microsoft anticipate this and require that icons be plain white silhouettes on top of a solid color when placed on a tile? That way, the third-party applications would match the Microsoft applications in appearance.

Actually, isn't there still time to fix this now that it's apparent that it will mess with the user experience in a major way and degrade the basic aesthetics of the main screen?

[bztzt]

If you don't like the app's tile you can unpin it - personally I like having some variety to my start screen.

It would be pretty hard to enforce a lot of visual uniformity considering that live tiles are meant to surface content, including things like photos. You'd have to enforce rules on what people's friends can look like.