Proof that users will be confused about the similar names of Amazon's Appstore for Android and Apple's own App Store is a "stumbling block" for Apple in its trademark claims against Amazon, according to US District Judge Phyllis Hamilton. Hamilton made the comments during a hearing on Thursday, noting that she was "probably" going to deny Apple's motion for a preliminary injunction against Amazon in order to stop it from using the term "app store."

Apple filed for a trademark on the term "App Store" in 2008 and was initially rejected, but then approved in early 2010. Microsoft was the first to file an objection in July 2010 on the grounds that the term was too generic, and later asked the Trademark Trial and Appeal Board to issue a summary judgment denying Apple's trademark application.

That never stopped Apple, though; in March of 2011, the company filed suit against Amazon after Amazon began marketing its own Appstore for Android. At the time, Apple said that Amazon was guilty of trademark infringement and unfair competition, arguing that third-party use of the term "app store" had only occurred in limited circumstances and that Amazon was using it improperly in order to confuse customers. Amazon responded to the accusations a month later, insisting that the term is generic and that it wasn't confusing Apple's customers.

During Thursday's hearing, Judge Hamilton told Apple that the case wasn't going well for the company, as she had yet to see any "real evidence of actual confusion." Because of this, she wasn't particularly optimistic about Apple's claims and indicated that she was unlikely to give Apple the injunction it wants.

"I’m troubled by the showing that you’ve made so far, but that’s where you’re likely not to prevail at this early juncture," Hamilton concluded, according to BusinessWeek.

Meanwhile, Apple is still sending cease-and-desist letters to entities using the term "app store." An open source startup called Amahi posted on its blog earlier this week that it had received a notice from Apple asking the company to halt the "unauthorized use" of the term "app store."

"We’re still trying to determine what is the best course of action, however, this looks like a rather heavy handed move," the company wrote. "Amahi being literally nothing next to Apple (sigh) we do not have the resources to fight this battle."

Instead of wasting resources fighting Apple, Amahi has decided to simply try and rename its app store. But if Apple's motions against Amazon end up being rejected as Hamilton predicts, Amahi may want to reconsider. After all, "app store" is a pretty descriptive way to tell users that you're offering a number of programs to download, as Amazon has already learned.