From day one with the Apple TV, I have hated the way you enter passwords. Some bright UI designer at Apple felt that a single line of characters when you enter passwords was cool, but ignored the fact that it takes way too long to navigate that line.
Rob Griffiths found how to bring back the old password grid, which makes it much easier to enter passwords. Did you keep the remote from your previous Apple TV? Well, it will come in handy now.