NNID services like Miiverse, Pokémon Shuffle, Nintendo Badge Arcade, DLC shops in games etc are working just fine for me, after running CTR-HTTPWN.
I'm on 11.0 firmware though, are you suggesting much earlier firmwares aren't working with this trick now?
Updating the Homebrew Browser and HTTPwn seemed to do the trick. I didn't realize I'd downloaded HTTPwn long enough ago that it even NEEDED an update! March, seriously? Well, it's taken care of now. Thanks!