They have a group of designer/developers specifically dedicated to UI development. I remember mark saying that the changes will be incremental over some time as

They have a group of designer/developers specifically dedicated to UI development. I remember mark saying that the changes will be incremental over some time as they experiment and get feedback from community not drastic. If you look back in the last 2 Ubuntu releases you will see there has quite a bit of changes here and there, they all add up over time.