One other feature of MMX which must be mentioned is improved network interaction, as Intel pushes to overcome the 'bandwidth barrier' of the Internet.
The drive is towards applications that run primarily on the PC, with Internet updates only when absolutely necessary.
The best PC game ever, Elite for the BBC micro, overcame memory restrictions in a similar manner, only making occasional calls to the disk drive.
As PCs are so fast, and the Internet so slow, this seems the right way forward.
It could also mean a revolution in networked games.
POD is playable with a range of options, including multiple player scenarios with some participants on a LAN, and some connected across the Internet.
D oom and Quake may have set the standard for playability in these games, but playing them across the Internet is a whole new shooting match.
Videoconferencing should benefit from similar techniques, and may fulfil its promise with MMX.
One final caveat - MMX is likely to reduce performance on standard floating point applications, because it is so tuned to multimedia calls, but most users, whether business or home, don't really need the bravura performance of the higher specification Pentium processors anyway.