The SW-4261 would work in that application, however the quality will not be extremely high. Now the video streamed over the internet isn't necessarily high quality either, but the 4261 can only output from composite video (red, white, and yellow RCA connectors). With the external video conversion, I would say that the wireless PC to TV has about the same quality as an old VHS tape.
If it is possible for you, a better solution might be the
InternetVue adapter. It is a high quality PC to TV converter that works off of a wired, or wireless network connection. I'm going to go out on a limb and assume that if you are streaming videos you have a broadband internet connection, so you should have a good start. If your TV is within range of your wireless network then you are set. If you don't use WiFi, then you would need to run a network cable to the TV but the picture quality is tons better. You install a small app on your computer, and can send signals directly to the TV.
It does cost more, but if image quality is important it is well worth the difference.