My perception of WP8 start screen
As being an early WP7 user I am a bit disappointed with WP8 startscreen, i think these two pictures explain in a nutshell what I mean:
WP7 start screen perception:
WP8 start screen perception:
These small sized tiles and over animated flickering looks very "asian" to me, not that "swiss design" as it was stated initialy. Also i have to note that it is really annoying that app developers ignore default colour as background in their tiles, i really hope Microsoft prohibiting apps without "metrofied" tiles in Marketplace, because theme colour makes no sense in case if it is ignored.
P.S. Quick tip for Metro app developers, making a metro logo for your product is easy as that: just take your black-and-white version of logo from your brandbook and use it on a default colour background, that's it! I believe Microsoft SHOULD put this recomendation to their UI Guide.