According to the latest MacWeek (not infallible I know) Apple are
planning to support the DAV standard in future PowerPCs, just not the
very first ones to ship. They expect to include the DAV slot, adn
support for some of the DSP stuff, but the PowerPC is fast enough to not
need a separate DSP.
Also, I saw a report that Apple's Dave Nagel had anounced MPEG support
for the Mac at a Multimedia festival in Japan in November, but I haven't
seen this confirmed by Apple HQ.