Android media tablets collectively have been able to take 20 percent market share away from the iPad in the last 12 months, according to a report released yesterday by ABI Research. But Apple still rules the roost, with no single Android tablet vendor cashing in by a significant margin.

“Many vendors have introduced media tablets, but none are separating themselves from the pack to pose a serious threat to Apple,” said ABI mobile devices group director Jeff Orr in a press release. “In fact, most have introduced products at prices higher than similarly-configured iPads. Apple, never a company to be waiting for others, has introduced its second-generation iPad media tablet while keeping product pricing unchanged.”

Fragmentation has been an ongoing problem for Android, and it’s hindering growth in the tablet category as well, ABI says. Google’s Android OS has no less than three different software builds deployed across media tablets at the same time. “The benefits of open software platform development have yet to be realized for media tablets,” ABI says.

“De-featured,” low-cost media tablets are being introduced by more than 50 vendors in 2011, Orr says. “This will certainly help bolster year-over-year growth for the category, but it also creates a negative perception in the minds of the mass consumer audience about the readiness of media tablets to be fully functional within the next several years. Good user experiences and product response are needed to propel this market beyond the ‘early adopter’ stage.”

Worldwide annual media tablet shipments are expected to top 120 million units in 2015, according to ABI estimates. While not quite as strong as traditional PC or smartphone annual sales, media tablets are emerging from the shadow of non-handset mobile devices and rapidly coming into their own, the firm says.