Apple has filed for a new Trademark with the United States Patent and Trademark Office in August 2003.
The newest Trademark is "Garage Band", categorized under "computers, computer software, and computer peripherals; computers, computer software, and computer peripherals."
Apple still has a number of unused Trademarks. Most recently, they registered for a number of animal names -- including Lynx, Cougar, Leopard and Tiger, which could potentially be future OS codenames/releases. Other examples of unused Trademarked names include: Junkyard, XGrid, and Gigawire.
Keynote was first mentioned in a Trademark application in October 2002, and became a shipping product at MacWorld San Francisco 2003.