The move to product segmentation may make sense for VIA for the same reasons it has for Intel. Intel has been able to command a premium for its 875P chips versus its 865PE, for instance. VIA has more impetus to make this move, however, in order to manage the transition to PCI Express. VIA stands to gain lots of business by offering its customers multiple north bridge configs over the next year or so.
Based on the rumblings I heard behind the scenes, I'd expect all of the dual graphics north bridges coming (whether they be from VIA or others, and whether they be dual PCI-E or an AGP/PCI-E combo) to support something less than sixteen lanes of PCI Express bandwidth per slot. The question will be how many lanes the chipsets will provide to each slot, how many lanes total, and whether a four-lane or eight-lane config will hinder performance to any noteworthy degree.
Gatt also revealed details of the new VIA south bridge for PCI Express, which should have eight channels of 32-bit, 192KHz high-definition audio, four Serial ATA ports, two ATA/133 channels with support for two devices each, and at least two lanes of PCI Express to power PCI-E X1 slots. I don't believe he mentioned Gigabit Ethernet as a feature of the new south bridge. We'll check with VIA for confirmation about that one and let you know.