Tablets running Google's Android OS may be in large supply, but numbers won't be enough for the operating system to overtake Apple's iPad.

According to a Gartner report, Apple's tablet dominance isn't set to abate anytime soon. Gartner estimates point to Apple's iOS grabbing nearly seventy percent of the market in 2011, a commanding position that won't noticeably decrease until 2015, when it will drop to 47 percent. During that same span, Android's influence will increase from its current 20% market share to 39 percent.

But Apple and Google won't be alone. More players will soon join the OS battle, starting later this month with RIM's Blackberry Playbook tablet. Like Google and Apple, RIM's strength will lie in its ability to create a unified ecosystem across platforms, Gartner says. This is one area where most other tablet manufacturers have failed to make sufficient headway.

For this reason, Gartner sees limited potential in MeeGo and WebOS, the platforms developed by Nokia and Hewlett-Packard, respectively. Smartphone users will want to buy a tablet that runs the same operating system as their smartphone. This is so that they can share applications across devices as well as for the sense of familiarity the user interfaces will bring, Garner Analyst Carolina Milanesi said.

For Google, the Garner report paints a similarly-favorable picture to the firm's recent report on the smartphone market. Gartner estimates that Android will run on 49% of the world's smartphones by 2012.