Without host (n9) delivering power to peripherial device, you won't get data transfer, either. Y-Cable may help here, but you need it to deliver power via USB 5V line, at least for short while.
So, rather, it's "data transfer without charging" a nonsense, not the other way around.
I wouldn't hold my breath for N9 hostmode anytime soon (or at all) - at least, if kernel update project for N9/50 won't take pity on us, and implement required kernel bits, as side effect.
Actually charging works, as per the first post of this thread (at your own risk since if you forget any of the steps e.g. disabling bme you risk frying the device... albeit it seems that it is not as probable as I initially imagined).
