In an interview with Eurogamer, Blizzard Entertainment also linked a drop in subscribers to the launch of a rival Star Wars-themed title.
The firm revealed in November that WoW had 10.3 million subscribers, down from a peak of 12 million in 2010.
Others have attempted to make WoW work on Android devices, but an official launch could boost Blizzard's profits.
To date the firm has only released a free Mobile Armoury app to allow players to keep track of their characters and plan their adventures.
The developer's senior producer John Lagrave told Eurogamer that the biggest reason his team had not released a mobile title allowing gameplay was because of the problems involved in shrinking the interface.
"Maybe we'll stumble on the great way to put WoW on the phone - maybe we won't, but we're certainly looking into it," he told the website.
"The world is evolving towards that little handheld device... It would be foolish for any game developer to not be looking at that and we're not. We don't think we're foolish."
Competition
Mr Lagrave also signalled that the number of people paying a fee had continued to "dip" since the last time it announced figures.
Bioware and Lucasarts' Star Wars: The Old Republic launched in December, offering an alternative massively multiplayer online (MMO) experience.
Frank Gibeau, president of labels of its publisher Electronic Arts, told analysts in February that the title had already attracted over 1.7 million active subscribers with gamers' playtime averaging approximately four hours per day.
Blizzard began offering 20 free WoW levels last year, and Mr Lagrave said the idea of extending the trial was now "on the table".
But he added that he expected a rebound in numbers once an expansion pack is released. The Mists of Panderia update - whose release date has still not been revealed - will allow players to explore a "lost continent" populated by panda bears skilled in martial arts.
The firm has also announced that it had renewed its partnership with Netease in China, ensuring that WoW can continue to be marketed on the mainland.
Streaming solutions
While Blizzard ponders a mobile WoW release, others are attempting to step into the breach.
Vancouver-based Gamestring announced in December 2010 that it was trying to make the title run on Android-based devices.
It showed off an early "alpha-version" of a hack that allowed the game to run on an HTC phone by streaming data from its servers to a customised touch-based interface.
Users have also posted videos to YouTube showing the game running on tablet computers via remote desktop apps.
However, such solutions introduce the problem of lag and and are harder to control than on a PC.
source : bbc.co.uk