http://www.nintendo.co.jp/wiiu/support/system_update/index.html

Rough Google translation, joy!

 

HBC works fine apparently.

http://gbatemp.net/threads/new-wii-u-update-out-now.355413/

 

Any homebrew launched from HBC will not display correctly, you need to use a forwarder.

 

No, you just need set the sound mode to surround in Wii U mode, vWii will use the same settings.

Now we have the following options for audio:

No HDMI setup
Option 1: If your TV support PCM output and have optical audio output you are good, you will get DPII/PCM signals, no receiver needed, just connect the optical to whatever audio system you have, you still need a 5.1 audio system with optical input.

Option 2: Now we can use HDMI cable for image and component/composite (red/white) for sound, both at the same time, it will give you DPII output, not sure if PCM can transfer with this setting though, you still need a 5.1 audio system with RCA input (red/white plugs).

HDMI setup
You can get DPII or PCM sound formats through HDMI, but you need a receiver with at least 1 HDMI out / 1 HDMI in, in order to decode those formats, Wii U transfer the sound to your receiver, and the receiver transfer the image to your TV. It's the best audio setup available regards audio quality, but is the most expensive.

 

I updated my TV and save me from buying a receiver, my Samsung outputs PCM, it was a nice bonus for me, mine is UNF325000, serie 5, it's not the latest model.

I can confirm that the rear speakers works for me, Wii/GCN DPII games too, it's easily noticeable in Rogue Leader sound check, I also didn't know that TV could output PCM through optical, but this model does, in fact it leave you choose the output signal: PCM/Dolby Digital/DTS Neo 2:5