One feature of my laptop that has never worked in Linux is the SPDIF output. In Windows the socket glowed red to show that there was some sort of optical connection available. Since I don't have any digital audio equipment, the lack of a digital output didn't bother me. I also don't have any multi-channel speakers, so the inability to switch to 4.1 or 5.1 output didn't bother me.
Trying out the Live USB for Gnome 3.6 recently, I noticed the SPDIF light glowing on boot, and on investigation I found that a digital output was available. Support for my sound card is obviously coming in Linux.
Then a few days ago I noticed a post on the Debian forum describing how to install the Realtek driver.
I gave it a go and found that installing it gives me an option of using the digital output or switching to 4.1 or 5.1 output. It also seems to give me an option to switch to recording from the sound card, an issue which I bemoaned in my previous post.