In the great debate on Android vs. iOS, Android’s market share is always brought up in favor of the Google-backed OS. Recent studies show that Android has a staggering lead over iOS, accounting for more than 50% of all smartphone sales.

A lot of that has to do with the spark in growth Android has experienced over the last 6 months due, at least in part, to Apple’s delayed iPhone announcement. But even with its recent successes, Google’s mobile platform still trails iOS in total number of devices…

After months in beta, Google finally introduced its music service yesterday to the public. During the media event, as Apple generally does, the software giant touted off some of its recent accomplishments. And apparently, Android has just hit 200 million device activations.

That’s double the amount of activations that Google reported at its IO developer conference back in May — quite impressive. But it’s still not enough to top iOS. If you’ll recall, Apple revealed that it has sold over 250 million iOS devices during its iPhone event last month.

But how long can Apple keep its lead? After all, 50 million isn’t a very big margin when you consider how fast Android is growing. It’ll be interesting to see how each platform does this fourth quarter, especially with the holidays around the corner.

Between Android’s hot streak and the success of the iPhone 4S, anyone could come out on top.