Not sure if this was reported or not yet, but placing Glow Lichen in or on lava waterlogs it. If the Lichen is destroyed, the water remains as a source. Weirdly enough, this seems to work in both the Overworld and the Nether, but I have yet to test it in the end. So yeah, it makes water in the Nether. I've always wanted water in the nether in some form, so to compensate my "extreme sacrifice", maybe you could make this into a splash text or something? JK.

Pictured below is the result of placing both Glow Lichen and vines on a partially submerged block of cobblestone in a lava lake in the Nether. On the left, you can see the waterlogged lichen, and on the right you can see where the vines popped off and burnt up as an item.