Google’s Android-based tablets are seeing huge growth in terms of sales as well as  shipment, and has doubled up in the fourth quarter of 2010. On the contrary, Apple’s iPad is on the verge of becoming a declining market leader.  In fact, Android OS has won the overall market share from the iPad, and is expected to continue this trend throughout the first half of this year.

Strategy Analytics’s Q4 report suggested the overall increase in tablet shipment from 4.4 million in Q3 to 9.7 million in Q4.  Apple kept hold of 75 percent of market share, but had a reduced percentage by 6 percent. On the other hand, Android experienced increased market share from 2.3 percent to whopping 22 percent. Neil Mawston, Director of Strategy Analytics, reported that the main driver of Android’s success is the Samsung Galaxy Tab that was launched in several countries, and was heavily promoted by the company.  Moreover, low cost and an extended range of Androidservices helped it expand its market share and usership.

“Apple’s volumes will continue to go up, but market share will inevitably go down,” Mawston said in an interview. “Even at $500 retail, based on some of the research we’ve done, that’s probably two or three times more than what most mass market consumers are expecting to pay. If you were to ask me in two years time, will Apple have less than 50 percent of the global tablet market, I think that’s a certainty.”

Another report from Canalys showed that Android has become the best-selling OS for smartphones, even ahead of Nokia Ovi and Apple. The number of units shipped in Q4 has already increased from 100,000 to 2.1 million, which is really exciting for Google–not so much for its competitors.

Microsoft is also facing losses as its shares fell 3.5 percent on Friday and had reduced revenues in Q4, noting its sad state of tablet affairs during the earnings call.  However, the company recently revealed some important and interesting figures for Q4, 2010, with the sale of over 2 million Windows Phone 7 devices. T he overall mobile share of Microsoft may have dropped to 2.8 percent in Q3, but the customer satisfaction stands at 93 percent.

Nokia also faced a blow as Google’s combined OS efforts outshine Symbian’s market share in Q4 2010. While the margin was not so big, Android managed to sell 32.9 million phones as compared to 31 million of Symbian.  Android also managed to outshine both Symbian and Windows 7 in European markets by taking 15:1 margin for market share.