1) Photo Hub now sucks with out the Background pic.
2) The "Me" tile is horrible. Can't post to all the services at once anymore.
3) Facebook integration just got watered down. No more Messenger (and Skype messages for that matter) in the messenger app, no notifications in the Me tile, I have to now click a FB icon to see my albums in Photo Hub. FB is no longer an account in "Email and Accounts". And alot more missing.
4) Games in the app list.
5) No photo editing apps in the Photo hub, and no music apps in Xbox Music.
6) Can't rsvp to a FB event in calendar.
7) I actually miss the Music and Video hub. Not a big fan of the stand alone apps.
For all the great new features they added, its a wash with all the ones they took away. I can't believe I'm saying this, but I'm disappointed. When I upgrade to the Icon next week I wont be installing the update. This update is garbage. I was happier before. And if by the time I am forced to update, if all, and I mean all of my list aren't reverted back, I may wind up switching, as all the things that have kept me here for 3 yrs are gone. All the things that made WP unique and different from the rest are gone. Now there's nothing separating them from the competition, except for the UI/Metro and Start Screen.