The battle between Android and iOS may be getting more heated, with the rumored addition of a Google tablet store and future co-branded Google tablets.

According to unidentified “people familiar with the matter” who spoke to the Wall Street Journal, Google is planning to launch an online store for tablets, selling the devices directly to consumers and emulating the Apple/Amazon model.

The store will also reportedly feature some Google co-branded tablets down the line, similar to the Nexus One.

There have been persistent rumors for months that Google is planning on releasing a Nexus tablet, with a lot of speculation over whether it would challenge the price point and features of the low-cost Kindle Fire or move up-market into the iPad’s territory. Previous reports have indicated that tablet production could start as early as this spring.

In February, Android chief Andy Rubin indicated that Google was going to “double down” on tablets in 2012. The perfect opportunity to announce an effort of that magnitude is coming in June, when Google hosts around 5,000 people at its annual Input/Output developers conference.

Last year’s conference saw the introduction of Google Ice Cream Sandwich, which attempts to unify smartphones and tablets and address some of the fragmentation issues that still lie at the heart of Android’s ecosystem.

With the introduction (and integration) of Google Play, the company certainly appears to be making moves to compete with Apple and Amazon by unifying and bulking up its content offerings. But Google still lacks the breadth of content of either of its competitors. And no one Android tablet maker — Samsung, Motorola, Asus or others — has had a breakout hit apart from Amazon, which developed its own tablet operating system from the bones of Android.

Even with that weakness, Android tablets are still expected to pass the iPad by 2015, according to the latest figures from the IDC Research Group. Apple currently holds 54.7 percent of the world market, the report said.

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