An attempt by Apple to impose an injunction to stop Amazon from using the term "app store" has been shot down by a federal judge.  Amazon recently launched their Amazon Appstore for Android and Apple pounced, filing a lawsuit that claims that the name violates a trademark initially denied to Apple in 2008, but more recently granted in a 2010 appeal.  They also contend that Amazon is diluting and tarnishing the Apple brand.  U.S. District Judge Phyllis Hamilton denied the motion for injunction because she saw no evidence of dilution or tarnishment, and only a slight case for trademark infringement. 

As for Amazon, they argue that "app store" is too broad of a term to be trademarked, as it is widely used to describe any such marketplace designed to let consumers purchase software applications for their devices.  Microsoft, who is also challenging Apple's claim to the name, used a similar line of reasoning in their motion for summary judgment with the U.S. Patent and Trademark Office.  Amazon further contends that the "for Android" part of the name draws a clear line between Apple's iOS-only store and theirs.

While the full case has yet to be decided by the Trademark Trial and Appeal Board, a denial of injunction like this is usually a sign that the will not end the way Apple hopes. 

Source: Ars Technica