At the last minute, it switched out this feature in favor of low-power Bluetooth 4, which is probably way more useful to most buyers. Now, stereo is back, and it sounds great.
The trick here is to make two entirely separate speakers behave like two halves of a wired stereo setup. And the result sounds so much better than even two mono speakers together. The obvious use-case here is for watching movies on your iPad, but music will also benefit hugely from the extra stereo space.