In Q4 2010, Apple's tablet captured 75.3 percent of worldwide market share. Android-based devices grabbed 21.6 percent share, according to market research firm Strategy Analytics. Windows and other platforms made up the rest.

Apple thus lost about 20 percent of the market share pie to Google when comparing Q3 2010 to Q4 2010. Three months ago, Strategy Analytics said the iPad had 95.5 percent of the market while Android devices only had 2.3 percent.

Despite the huge changes, both Apple and Google are riding the tablet market explosion, selling more last quarter than in the one preceding it. In Q3 2010, Apple shipped 4.2 million iPads, while in Q4 2010, the company pushed out 7.3 million units. The total for last year was 14.8 million iPads. In Q3 2010, 100,000 Android tablets shipped, while in Q4 2010, 2.1 million units hit store shelves. In total, about 2.3 million Android tablets shipped worldwide last year.

We can expect both those numbers to further grow with each quarter this year. Furthermore, there will be another player: Research in Motion's BlackBerry PlayBook.