I've incorporated clean borders into my new addon, Clean UI. Please check it out!
Clean Action Bar Borders
This addon retextures the icon borders which show on the Action Bar and in the Skill Menu. Inspired by the clean look of the console UI and the addon AUI. Any addons that utitlize the default frames for buffs/reminders/etc will also be affected by this addon. View the screenshots for more information.
v1.2 NEW addon settings menu that allows you to switch between the default borders and Clean borders without exiting the game.