The springboard hack is just the removal of a app and creation of a blank space. Not that amazing, but whats important is the bypass of Nano’s cache comparison, which compares any modded SB file and reverts it if it doesn’t like it, this opens up the possibility of hacking and modding, while not adding bootloaders or any of that fun stuff.
Next is the discovery in some of the device’s plists of reference to support of Movies, TV Shows, Apps, Games, vCards, Calender events and so on, with a few other cool things like a passcode lock. With the bypass I figured out, I hope to enable these pretty soon. It seems like the OS is a rehashed version of the previous Nano’s OS.
Whelton is hoping to get a bootloader on the device to expand its functionality. You can follow or get involved in the new touch Nano hacking process at http://nanohack.me