When Tim Cook took the stage to announce the new iPad on March 7th, he spent some time talking about the post-PC era, for which Apple’s iPad was the “poster child.” In the two short years since Apple basically created the tablet market with the launch of the original iPad, tablets have become a major player in the personal computing market.

The prominence of tablets in this post-PC era is only going to increase, according to a recent report by Gartner. According to the report, tablet sales in 2012 will reach almost 119 million units across all models, of which Apple’s iPad will account for almost 73 million units. What’s more, those numbers will only go up in coming years, if Gartner’s forecast is correct. They project tablet sales to reach 182 million next year, and a staggering 369 million – over a third of a billion tablets – by 2016.

Interestingly, they project that Android tablets will grow to rival – but not surpass – the iPad. As you can see from the chart above, the projection for 2016 shows Apple maintaining a solid lead in the tablet market, with Android coming in a relatively close (i.e., 30 million fewer units) second. They attribute this to the current lack of tablet-optimized Android apps. While Android has done enormously well as a smartphone platform, its performance as a tablet platform has lagged behind somewhat. Gartner foresees that changing in the coming years as the Android tablet app ecosystem improves.

They also project decent performance for the forthcoming Windows 8 tablet market. They project Windows 8 tablets selling a modest (but respectable) 4.8 million units after their launch this sometime this year, with Windows 8 surpassing 2011-level iPad sales in 2016.

What do you think of Gartner’s projections? Will Android ever pass Apple in the tablet market? Will Windows 8 tablets be a success? Let us know in the comments.