There was speculation in this thread about whether the name "iTunes Music Store" protected Apple from this suit because it did not feature the word "Apple". We now know better.
From Royal Courts of Justice court papers:
The alleged breaches come about in the following manner. Computer has launched a web-based product in the United States called iTunes Music Store. By using that service members of the public can download songs over the internet, and store them on a computer with a view to playing them back over the computer, or via portable players such as Computers well-known iPod player. Computers mark is clearly associated with that product it appears on all the relevant pages, and one gets to it either via the Apple website or via a website known as Applemusic.com. The content (that is to say, the music tracks) is licensed by the owner of the rights in that content. Corps case is that Computers conduct in this respect is a breach of the Trade Mark Agreement; that is the breach which is relied on in this action as currently constituted.
("Computer" means "Apple Computer" and "Corps" means "Apple Corps".)