For those that are interested in an alternative I finally got around to running my cables from my PC to my HT system. (DVI to HDMI and an optical for audio) The cables cost about a third of what the Roku cost, but obviously the hook up is not as convenient.
I get three bars showing with their quality test, and the picture quality is actually quite good. Better than I expected it to be. Just like the Roku the audio is only stereo. Of course most receiver have Dolby Pro Logic and other multi-channel matrix programs, but that's about as good as the audio gets.
My PC is more of a gaming rig than a HTPC. The video card is a GeForce 8800GT and I'm currently using the on-board Realtek audio. Both capable of HD, but really nothing special when it comes to Home Theater.
One added benefit from running cables is you gain full PC functionality to your big screen as it is simply a duel monitor setup. Something the Roku can't do, AFAIK. Surf the web, stream PC radio stations, and other free video websites such as Hulu. PC Gaming is also possible, but I will be upgrading my soundcard so I can get 5.1 in games. The on-board audio does not have this feature. Oh, I guess one more benefit. If your DVD player is on the fritz you can play DVDs from your PC. Most on-board audio will pass 5.1 DVD audio through the optical cable.
The only con is you will have to run the cables. Not something everybody is able or willing to do. I was remodeling the two rooms that have my PC and my HT, so I was able to run the cables into the basement and add wall plates to give it a professional finished look. The hookup and PC configuration is pretty straight forward, though.
Well, If anything I'm really loving the added media library Netflix brings with the streaming option. A feature I very rarely used before I had it hooked up to the big screen.