So, I just learned this from here
- Paperwhite serial numbers: B024 (Wifi), B01B (Wifi+3G)
- Firmware version: Kindle 5.2.0 (1729740065)
This is pretty much what I expected. Although there seem to be some serious UI changes wrt 5.1.0, it's still just an evolution of the "old" K5 firmware, not a complete revolution.
This also means that hopefully, many of the previous hacks & patches for the Kindle Touch can be ported (and hopefully with relatively little effort) to the PW. And maybe we don't even have to reinvent the wheel for the jailbreak either? We'll see.
Note: I don't have a PW yet. I expect mine to arrive here in about 4-6 weeks.