Apple is expected today to unveil iOS 6 , the company’s next iteration of its mobile operating system at its 5-day annual Worldwide Developers Conference (WWDC).  

“We have a great WWDC planned this year and can’t wait to share the latest news about iOS and OS X Mountain Lion with developers,” said Philip Schiller, Apple’s senior vice president of worldwide marketing. 

Apple unveiled iOS 5 at last year’s event, and speculation has run rampant recently about what kinds of changes Apple will unveil this year. Reports of deep integration of Facebook and a new Apple maps product are tops on most lists of possibilities.  

Ahead of today’s event, Google’s Executive Vice President of Android, Andy Rubin, tweeted last night that Google is currently activating 900,000 Android devices per day.  Incidentally, Rubin also put an end to rumors that he might be leaving Google, tweeting, “No plans to leave Google. Oh, and just for meme completeness — there are over 900,000 android devices activated each day :-)”

Apple will undoubtedly push back against Rubin’s claims during today’s opening keynote at WWDC. The company has a long history of running down its impressive stats, revealing everything from device activation numbers to total number of app downloads. 

Apple’s late CEO, Steve Jobs, famously contended that Android’s numbers were inflated, because he said Google included upgrades in its activation numbers, while Apple only includes new activations. 

As of the first quarter 2012, Android controlled 56.1 percent of the smartphone market by operating system, according to Gartner. Apple’s iOS followed in second place with 22.9 percent of the market, up from 16.9 percent in the first quarter of 2011.