Fuzzy: Yes, there are indeed TV receivers available with USB. One of them is the Plextor PX-TV402U (aka ConvertX PVR), which is able to convert analog audio/video into various MPEG variants ready for VCD, SVCD and DVD as well as a DivX variant.
Driver source for Linux is available. If someone wants to have a go, I would be interested in sponsoring the development.
Unfortunately, there is no variant available with a DVB receiver.