The free market, in all its terrible beauty, is Apple’s most friendly enemy. After 18 months of being effectively the only tablet game in town (as a function of sales, anyway) the Cupertino giant’s deathgrip on the slate market is starting to crack. According to IDC, Android’s share of sales in the fourth quarter of 2011 will reach 40.3 percent of all tablet sales. That’s up considerably since the third quarter, which has been variously projected as 20-30%.

The rise is largely coming from relatively cheap Android tablets like the Nook Tablet and Kindle Fire, sitting in the $200-250 range in the United States. Overseas budget tablet makers from China and a few low-priced options like Archos are also seeing heavy demand, and Samsung’s Galaxy Tab line of devices remains one of the most popular high-end options. Asus made a considerable dent in the market with its dock-enabled Eee Pad Transformer, and the quad-core sequel known as the Transformer Prime is just now becoming available in the US and other markets. With Ice Cream Sandwich now available as an open source package, expect to see many more low-priced tablets running Android 4.0′s large-screen interface.

The iPad is still projected to control 59% of the tablet market this quarter. That’s a considerable lead, but not insurmountable – Android smarphones have pushed the iPhone out of the spotlight in the last year, outselling the Apple hardware two to one in some markets. It looks like Android is finally beginning to jump in tablet sales as well, and a repeat of its world-conquering smartphone performance is not out of the question.

Of course, failing actual innovation or competitive pricing, Apple’s legal team has been working overtime trying to halt tablet sales in Germany, Australia and the US. Germany is still upholding an injunction against the Samsung Galaxy Tab 10.1, and Apple has already filed suit against Samsung for the revised 10.1N model. Australia’s courts threw out Apple’s injunction against the same model after an appeals process, and the US denied the injunction, though penalties for design patent infringement may still be enacted. Apple’s also targeted HTC, which is currently facing a possible import ban in the US.

[via eWeek]