Who to believe?
Gartner seem to think Android currently only has 29% of the Tablet market.
"Gartner predicted an eight-fold increase in sales of devices that use Google's (GOOG) Android operating system over the same period, reaching 137.7 million units. Android's share of the market will rise from nearly 29% to 37% during that period, the firm said."
However IDC say Android tablets are at 44.6% (compared to Apples 54.7%)
http://techcrunch.com/2012/03/14/idc-apples-ipad-rules-tablet-sales-today-but-android-makers-will-overtake-it-by-2016/
"Overall, Android tablets accounted for 44.6 percent of all sales"
Personally, I would believe the IDC figures (or perhaps the Gartners ones don't include the Kindle Fire or something), as I know more Android tablet owners than Apple tablet owners, but that might be because I don't hang out in coffee shops all day, or work in marketing and PR.
Either way, this is all bullshit, i'm guessing Apple paid for the former report and Google paid for the later.