Comment 1 for bug 410337

There is one issue that needs to be addressed. Some users will expect to be able to press Enter as soon as the login screen appears, in order to quickly access the password entry screen.

The proposed solution has been added to a wiki: https://wiki.ubuntu.com/DesktopTeam/Specs/Karmic/LoginExperience#Login%20screen%20with%20user%20picker%20and%20more%20than%20one%20user%20account

The user name displayed at the top of the list should not be selected by default. Pressing Enter should result in selecting the user from the top of the list, unless any other menu item or button has been manually highlighted.