1. They have customized size and band, while not the shape. I for one love round shape and hate the square shape, and I believe I'm not the only one with this preference.
2. They emphasized too much on the interaction with watch. IMO, watch is supposed to notify you new things, have you glance over it and do some quick responding. That's it. User should not use watch in the same way they use phone.
In Apple watch's demo, they have too much interaction showing there and the information on one screen is sometimes crowded. That's not a good sign.
I do like the new interaction pattern they introduced there though. Quite innovative IMO.