Looking for way to get good audio from netflix

Netflix does stream surround sound, limited to 5 channel currently. I use an Apple TV and the multi-channel indicators light up when surround sound is fed. I have talked to them about this on the phone, and not all movies are streamed with surround. It depends on whether the version they own rights to includes a multi-channel track.
The sound quality is OK. I still depend on Blu Ray and my B&W 6 series speakers for great movie sound. I've never watched a Netflix movie and thought, "man the sound really sucks." I typically turn off my critical ears for Netflix, tho.

Why not just use VUDU instead? It does DD+ 7.1

Your BR Player or TV may already stream it.

I have a Sony Bravia that streamed Netflix with a dongle, and I could not get multi-channel out of the TV's optical port. Network stations coming in on the digital tunre put out DD+ just fine. I had to go to a separate component to get DD+ from Netflix. The Sony's internal board is not set up to output multi-channel from sources other than the tuner...so be careful of that!

I have ordered the Roku 2 HD, and looking at my TV manual it says to run an optical cable out of the TV for digital sound signal with the Roku coming in HDMI. I have the Sony XBR Bravia; my Blue-ray player doesn't do streaming video, and my hometheatre receiver is an older model without HDMI but does have an optical input. I was hoping for two channels plus adding a sub-woofer in the future. I am trying to keep this setup simple, but with decent sound quality, by avoiding the dacs in the TV and Roku I hope to get what I am looking for.

Does the Roku have an optical output, if so, run the audio through that into your receiver. cut the TV out of the signal path for audio if you can.
I looked at the Roku's back panel on the internet, I see an A/V outlet, but it doesn't look like an optical port...if it's not, and your solution doesn't work for some reason, the apple tv does have an optical port on the rear panel, if you want to switch up.