Four years from now (i.e., in 2015), Android tablets will closely match Apple iPad’s sales. Apple will continue to lead in the tablets market–but only until 2015. Thereafter, Apple will be turning over the reins to Android. These are some of the forecasts that David McQueen, principal analyst of Informa Telecoms and Media, reported in “Tablets: Segmentation, Mobile Operator Business Models and Forecasts.”

McQueen foresees 87 million Android tablets and 90 million iPads sold by 2015, with sales of Android tablets brisking up from 2013 onwards and eventually overtaking iPad sales in 2016. By 2015, Apple’s market share will drop from its current 75% to 39%, while Android’s market share will grow to 38% on account of two things: (1) the entry of cheaper and more advanced Android tablets into the market and (2) improvement in the ecosystem around Android.

Apple currently leads in three areas that McQueen considers to be critical factors for success in tablets sales: “brand, access to distribution channels, and product quality, including the application environment offered.”. However, the analyst also forecasts that as the quality of competitor tablets and their respective application environments improve, Apple will most likely lose its edge.

Four years is arguably a long time. But, 2011 already saw a growing list of Android tablets that can potentially shorten that time. And, with Android 2.4/4.0 Ice Cream Sandwich coming this last quarter, four years may really just be too long a time.

What tablet do you already own or are you planning to buy?