Sling is far better than a TV Tuner card. I have had a Sling AV controlling the cable box in the bedroom for TV on the PC and at work for a few years. There is a Sling Pro that can stream HD content, but you lose surround sound. That is not too big a deal given that many users will not have surround on the PC they stream to. The picture quality when streaming on the home network is better than any TV card I have tried as teh box and software do a great job of deinterlacing.
I have a 4G EEE PC that has been upgraded to 2GB of system memory and has an add on 8GB SD card. With Windows XP installed, it does a great job of running the Sling player software. On the home network, it rolls up to a 3Mb stream when set to the next to highest stream quality. The Desktop will run at 5Mb and produce outstanding results.
Depending on your ISPs upstream limits, you get anywhere from normal youtube (200Kb/s) to better flash player quality (500k-1Mb/s) unless you have FIOS, in which case it'll look like it does on the home network as long as the network you are on has the bandwidth.
The Sling AV is a great product, can't recommend it highly enough.
And crainger, you can manually set the stream size to conserve bandwidth.
Brian - aka HalcYoN
Nikon D700 and D300s | SB-600 | Tamron 28-75/2.8 | Tamron 17-50/2.8 | Nikon 70-200VR I
10.5/2.8 Fisheye | 28/1.8 AF-S | 35/1.8 AF-S | 50/1.8 | 105/F2 AF-D | Sigma 150/2.8 Macro
Nikon J1 | 10-30VR |30-100VR | 10/2.8 | 18/1.8