EDIT: Well, a few minutes later Dave Zatz posted with a lot more details, including photos and some development info. Nice work Dave!
As was widely speculated, after the Alpha software was seen at CES2006, the problem TiVo had was keeping the content locked down with DRM. Like it or not, that's a requirement for the business reality of even having TTG. So they turned to Sonic, who had developed the first commercial DVD software to support TTG on Windows, to help. And that got us to today, with Sonic building support for TTG right into Roxio Toast. That does explain, at least partially, the long delay. They literally started over from scratch.
The new software has four components: TiVo Transfer, Player, DVD burning, and Portable conversion.
TiVo Transfer was largely written by TiVo, and it bears a distinct resemblance to the Windows TiVo Desktop transfer screens.
Player, from Roxio, uses technology from ElGato.
The burning, built into Roxio Toast, allows you to burn DVD archives of the .tivo files, or burn video DVDs playable in a standard DVD player. And it creates TiVo-styled menu screens, which are customizable. It looks nice.
Conversion for portables converts to 320x240 resolution MPEG-4 or H.264, and it will automatically add iPod conversions to iTunes.
Toast retails for $100 and it will be available for order and download 'today' (I take it that means Monday). There are discounts/rebates for upgraders. And the first 5,000 people to buy directly from TiVo.com (from the aforementioned http://www.tivo.com/roxio) will get a free TiVo 'Glo' remote - the same remote used by the Series3, a $50 value. (It is very nice.)
It will be available for both PPC and Intel Macs running MacOS X 10.4. And you can create custom conversion profiles for other portable devices.