Confirmed to still exist in 13w07a.
This has always been the case, and probably isn't really considered a bug per se, but it would be nice to see it changed. Especially now that we have TNT minecarts. 😃
I literally realized what I had done the second I submitted this. Thanks! :3
I can verify this happening in my Nether (new chunks generated in 13w01b), looks the same as the broken-up fortress in the screenshots. I've specifically avoided generating any new chunks in the Overworld because of this, so I can't comment on that.
Also, my world is in Survival mode, whereas this bug is defined as Creative. Doesn't seem to make a difference.
I agree with Thimo, I believe this is supposed to happen. It's always happened as far as I can remember. It can get annoying, but it makes sense to have "electricity" short circuit a bit when hit by water.
Still affecting 1.9.4