Here's another solution for streaming TV in your home or over 3G: Hauppauge Computer Works has just announced the new Broadway box. The US$199.00 device has a built-in HD H.264 video compressor, an ATSC tuner for local broadcasts, and support for QAM digital cable, so if that's all you want, the box can be used on its own. It also allows hookup to your cable or satellite box.
The programming you select can be viewed over Wi-Fi or the Internet on any iOS device. Details are a bit sketchy, and despite the announcement at CES 2011, the Broadway hasn't even shown up on the Hauppauge web site.
It looks like a solid competitor to the SlingBox line, but we'll wait until we actually see one