Ben Evans has interesting data on how the tablet market is splitting:

If this theory is correct, it suggests that Apple's $300 Mini really isn't a competitive problem, because the iPad doesn't yet face a strong competitive threat (quite unlike the iPhone). Rather, there are actually two quite different markets: the post-PC vision, where Apple is dominant, and a ultra-low margin product that’s also called a tablet but which is really a totally different product.

Precisely what I said to Mail Online after Tuesday's Apple Event, though they chose only to use a small quote in a mostly Apple-bashing piece.