Do we really want the PC to head in this direction? It was different back in the days of the classic Amiga's with the A500 & to a lesser extent the A1200. The A500 in particular with its custom Video & Sound capabilities were literally years ahead of the competition at the time,which meant the Computer was designed to last a few years.
Compare this to the low-end PC solutions of low grade Celrons with Intel810/15 integrated graphics & sound with no AGP slot, or integrated Athlon Via M/B.
These low-grade options today are not adequate at handling anything other than old low grade games,or purely business applications. If you want an all-round quality PC you have to pay for the sufficient expansion options,(AGP,PCI,USB,firewire,RAID etc.).
The differences between these shoddy low-end M/B footprints & the Amiga's,(for their capabilities at the time),make them incomparable. Until someone comes up with a sufficient design,(& I understand Nvidia has made an attempt with their chipset for the Athlon),they shouldn't bother.