Looking for way to get good audio from netflix

Roku is very good both picture wise and sound wise

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.