Brian English

I can confirm this happens on Windows 10 edition.

Same issue with Windows 10, here.

I'm having the exact same issue - I just uploaded two screenshots showing lighting errors in 1.2.1 which were not present in 1.2.
The first (minecraft1) is of a torch placed at the end of an otherwise unlit tunnel I had just dug. The second (minecraft2) is what my Minecraft looks like if smooth lighting is turned off and the game reloaded,

I don't have a screenshot, but the Nether also basically fails to render more than 8 chunks' worth unless I go to the edge of the "void", at which point it renders more... but it's still not working properly like it did in 1.2.