VIA's upcoming VT8237S south-bridge will implement a serial bus that will allow easy BIOS flashing for the likes of system integrators and motherboard manufacturers.
Generally speaking, there are two ways to program a motherboard's BIOS. The first is to use a software flashing utility, be that a component of the BIOS itself, a text-mode (e.g. DOS) application, or a Windows program. For developers, or those who manage to completely do over their BIOS, it's a case of popping the chip into a flash reprogrammer and downloading a new BIOS image onto it.
VIA has been working with a company called DediProg to implement a bus on its new south-bridge that will allow easier BIOS reprogramming. The SPI, or "Serial Peripheral Interface" bus, is a simple 4-wire bus - nice and easy to implement - designed for (believe it or not) serial data transfer. One pin for a clock, one for data in, one for data out, and one for chip selection.
For easy BIOS reprogramming, a Serial Flash hardware device, such as those made by Dediprog (naturally), can be connected up to a four pin interface on a PCB and bam... flashed. This can be done without powering up the device and of course without removing the BIOS chip.
System Integrators might see it as an easy way of updating stock BIOS images to include boot logos or other features, while motherboard manufacturers might find it easier to debug development BIOS versions (although we're pretty sure motherboard manufacturers have tried and tested systems for doing this already.)
Another use we can think of for the funky bus is for custom BIOS projects like LinuxBIOS; a GPL'd BIOS that can be flashed to compatible motherboards and get you to where you want to be (network boot, serial interface, Linux console) in three seconds or so. We reckon Linux BIOS folks could benefit from an easy reprogramming method such as this.
Still, we'll have to see if SPI headers actually appear on any production motherboards with VIA VT8237S south-bridges, or if they'll be reserved only for pre-production models (though even if no headers are present, the bus will still be there somewhere, should anyone be handy enough with a soldering iron...).