According to the new tablet forecast from the analysts at Gartner, Apple's iPad will dominate the tablet market for years to come. Up until 2015, iOS will account for over half of tablet market share. In 2011, 69% of media tablets will run Apple's mobile operating system, but that number will slip as Google's Android operating system takes hold, the firm predicts. By 2015, 39% of tablets will run Android, says Gartner.

According to the forecast, Apple's iOS will account for 68.7% market share in 2011, as determined by worldwide sales. In 2012, it will still be a strong 63.5%, but by 2015, it will fall to 47.1%. By then, Gartner predicts that Android will have grown from 19.9% market share (2011) to 38.6% (2015).

Meanwhile, RIM's soon-to-launch QNX OS, the OS powering its PlayBook tablet, will reach 10% by 2015. HP's webOS will be at 3% and MeeGo will reach 1%.

Issues with Android

Currently, Apple's competition is competing via hardware features and specs, not "applications, services and overall user experience," explains Carolina Milanesi, Research VP at Gartner. When tablet makers realize their mistake, they'll have a better chance at fighting Apple, she says.

Gartner also says that Google's decision to not open up Honeycomb, its first tablet OS, to third parties will slow the price decline and ultimately cap the market share. "The new licensing model Google has introduced with Honeycomb enables Google to drive more control, allowing only optimal tablet implementations that don’t compromise quality of experience," said Roberta Cozza, principal analyst at Gartner. "This might mean that prices will drop at a slower pace than what we have seen in the smartphone market."

While Google is reportedly exerting more control over Android, it's unclear from this report if Gartner understands that Google will be open-sourcing its tablet OS, just not in the short-term. From what we read on the official Android Developers blog, it sounds like Google is waiting for Android Ice Cream before open sourcing the code. Ice Cream (or Ice Cream Sandwich, perhaps) is the unifying OS that brings Honeycomb features to phones.

"As soon as this work is completed, we’ll publish the code," wrote Google chief Andy Rubin. "This temporary delay does not represent a change in strategy. We remain firmly committed to providing Android as an open source platform across many device types."

The App Question: Will Users Match Tablets to their Phone?

Another notable prediction from the new report says that users will want to buy a tablet that runs the same OS as their phone, so they can share apps across devices. While that's obviously a bonus, we're curious how much of the tablet purchasing decision is influenced by these sorts of app metrics as opposed to other factors, like Web browser performance, email functionality, unique features and price?

A recent survey from Google looked at the many ways people use tablets today. 84% played games, the survey said - and that's obviously an area where Apple's iOS wins at present. But at #2 (78%) was "searching for information," #3 (74%) was "emailing," and #4 (61%) was "reading the news." These are all areas where Google has key products (Google Search, Gmail, Google News).

This leads us to wonder - will it really be about picking the tablet that cross-syncs apps with your mobile phone? Or will it be about picking a tablet where the apps for your top use cases function the best? E.g., Gmail vs. iPad's mail client? Full Web (with Flash) vs. iPad's Safari? (Yes, we know: that's either a pro or a con, depending on your feelings about Flash). Or at the end of the day, will it all come down to price, another area where Apple is succeeding?

What do you think about Gartner's tablet forecast?