Swedish company PopCatcher has developed technology that's going to be a lawsuit waiting to happen if it hits US shores: its software is able to tell the difference between music, speech and commercials, and the company's MusicDock MD-601 automatically captures those songs, storing them as 192kbps MP3 files onto its docked MP3 player. Whoa!
HD Radio (listening now) is a proprietary In Band On Channel (IBOC) method for transmitting digital signals on the edge of the existing FM And AM radio bands. Quality isn't bad, but it's about comparable to a 96-128bit MP3. Range is a big issue since the digital carrier signal is broadcast at about 10% power, but a very good antenna will get you most channels in a big city. As the digital signal fades, your HD radio will "blend" audio back to analog.
The main benefit of IBOC, and the reason Big Radio pushed for it vs. completely new DAB frequencies (in the US), is: 1) the existing radio stations already own the bandwidth, and 2) a private company, Ibiquity, controls the (expensive) licensing; further guaranteeing small players will be largely shut out from radio.
Radio will probably always exist in some capacity, but the (so far) unsuccessful push for IBOC digital will help emerging media prevail. In a word, podcasts are better. KATG forever :)