Stability is the 1st thing that comes to mind. I never ever have to reboot my HTC HD7. So looking forward to a Lumia 900+ (Rumor has it that T-Mobile will get a slighlty updated 900) on T-Mobile later this year. The 1 Android based phone I had needed to rebooted daily. Most everyone else I know that has an Android based phone reboots often.
#2 is the Metro UI. It isnt the tiles its is that the tiles are live with information. Someone earlier complained about the people tile that it had random tiles. They are not random at all those are pictures of your friends and contacts. Live Tiles are all about my life, my contacts, my social networks, my wife, my kids, weather where I live, my stock portfolio, me...me...me. It isnt just a grid of icons.
Its libraries that sell systems not a single game.
