It's only a matter of time before Android overtakes iOS in the tablet space.
The open source nature of Android is perhaps a double edged sword, depending on how you look at the situation. On one hand, fragmentation is a sometimes annoying byproduct of having so many different device makers putting their own spin on the operating system, which is why Android 2.3.x (Gingerbread) is still the most popular version of Android to date. On the other hand, it's the very reason why Android's market share is so much higher than Apple's iOS platform. The one exception is tablets, but given enough time, it's inevitable Android slates will outnumber the iPad.