Overall, we still need another generation of CDRW recorders to pass
before a VDR (Video Data Recorder) using CDs is viable.
The problem isn't speed, its latency.
Even the massive IDE hard drives that can be bought these days are
barely acceptable for high quality/high speed recording and encoding
of a video stream. And that will become even more of a problem as
the original video quality improves (DVD, Satellite, and HDTV sources).
We are only just seeing CDRW recorders that can come close to
the sustained data rate needed for VCD quality video.
(I'm not making a prediction here, but)
The first systems to enable VDR will probably have a fairly fast
hard drive to record/encode the incoming video stream, and then
pass that stream to the CD-Burner as a more "permanent" recording.
VCD is a variant of the MPEG-1 spec, meaning it has lower resolution
and data rate than MPEG-2 (DVD specs). This results in lower average
video quality, particularly if you are trying to fit more than an hour
of video onto a single CD. VCD became more popular in the eastern
markets while the west held off in favor of DVD standards
(DVD was more acceptable for recording a full length film on a single
side of a single disk).
DivX is a variant on the MPEG-4 spec (actually, its started as a hack
of the Microsoft MPEG-4 Codecs). Because of that, it will never be
officially accepted as a video standard by any company that wants to
stay in business with the MPAA and DVD consortiums.
(MPEG-4 will be released by TPTB in some other form, because it can
offer the same quality as MPEG-2/DVD, with much better compression).
DivX/MPEG4 is also likely to be a more expensive format, because it
needs more CPU horsepower for encoding/decoding than the earlier formats.
Expect to see VCRs and TiVo/ReplayTV remain the standards for home
recording for a few years to come.