Duracell vs Energizer
Apple will survive because of the bling factor,
AN Other in the Android space will survive, because they're good products (I'd bet on Samsung here)
and then you'll get a smattering of small brand or no brand companies filling out the bottom of the market. Like the home battery market, there'll be a couple of big distributors who will spend a little bit of time fettling their products and a lot of time promoting that they have better product than the competitor, whilst the bottom of the market is filled with elcheapo variations on a theme.
N.b. Microsokia I think may replace Blackberry at the Enterprise (for those below C level), simply because of Windows penetration level, but you're never going to see massive market share.