http://www.hdbeat.com/2006/09/06/whats-so-great-about-the-series-3-tivo/
Many of us can't wait to get our hands on the latest HD DVR; the TiVo Series 3, but others are left wondering why it costs $799, not to mention the monthly service fee. Other than the fact that you hate your SA8300 or Motorola 6412 or DirecTV is letting you down with their HD selection, these are some the reason the TiVo series 3 should be so great. The Series 3 is the first stand alone dual tuner HD DVR for cable or OTA. It will not be the same as the TiVo made available via Comcast or Cox, those boxes will run on existing Cable Co hardware. ie. Motorola

Confirmed features

CableCARD support for recording two encrypted digital cable channels at once or one multi-stream Card when available. (Cable Co is required by the FCC to support)
NTSC, analog cable and un-encrypted QAM support.
Record OTA or Cable, with two inputs, which will enable the two sources to be integrated.
Expand your storage with a external eSATA hard drive.
Front panel display, which will show what is recording among other things.
New remote that is weighted to make it easier to find the top and back-lit which makes it easier to use in the dark.
Home Media Engine
Ethernet port
Dual USB ports
HDMI TOSLINK and Component Out

Expected
Multi-Room Viewing
TiVoToGo
Requires monthly TiVo subscription, $13-$20 month depending on Monthly commitment.
All sources will integrate into one guide.
Bring your own eSATA drive or only support TiVo brand.
Map un-encrypted QAM channels without a CableCARD.
Support for MPEG2, AVC and VC-1.
External Drive will not be easily moved to other units.
Initial call via Internet.
Hackable to add features or storage.
300 GB drive.

Left out
Will not work with VOD or PPV. (requires CableCARD 2.0)
No Support for Switched Digital Cable Systems.
No 1394 aka Firewire. (No archive to DVHS or PC)
Not able to record via component. (Will not record Satellite)
No S-Video/Composite in. (not able to record SD via external tuner)
No 500 GB drive option.

Features we really want.
Multi-Room Viewing (MRV) for those who aren't familiar with this feature, it enables multiple TiVo's to play together on your home network. Want to watch a program that is on another TiVo, no problem, do you already have two shows scheduled to record, TiVo will ask if you want to record it on your other TiVo.

TiVoToGo; this feature goes without saying, this should make up for the lack of 1394 port and enable you to transfer your shows to your computer and even a DVD, but don't expect to fit more than a half hour on a single layer disc, it may be time for the next generation optical disc.
CableCARD support, this will be the first of it's kind, sure you may be able to build your own Windows Media Center PC for less than the price of a Series 3, but you won't be recording Hi-Def digital cable.

Is it worth the price?
Those are just the specs and features, there are more immeasurable reasons that can only be known to those who have owned a TiVo. The best part is that you have another choice, you can choose the inexpensive version from your cable company or you can step up and buy the ultimate HD DVR available. For all practical purposes the Series 3 will be a high-end product for those who demand the best and are willing to pay for it. Sure it may not be right for everyone at that price, but when you are ready to step up, TiVo will be there for you and in the meantime they will push your cable company to improve their offerings. Is the Series 3 worth the price? How much would you be willing to pay?

Check back for a full review when it hits the street.

[Thanks, Dave Zatz and megazone for the details and pictures!]