Engadget, in their first impression, pointed out something I hadn’t yet read:
Movie selection is done completely within Netflix’s site, so don’t expect to do any browsing through the device interface. If you want to load and watch any content on the box, you have to make sure it’s in your Netflix Instant Queue through a browser. This part is definitely the biggest drawback for power users, but it does ensure a crazy simple device UI with zero learning curve.
Definitely not a dealbreaker, but a drawback nonetheless.