Do you hear that noise emanating from Santa Clara? It's the sound of the death knell for the PCI bus, and Intel's ringing it. Word from Santa Clara is that the world's largest and most influential chip maker will officially stop supporting the still ubiquitous PCI bus and switch solely to PCI Express with the company's upcoming H67, P67, and H61 core-logic chipsets intended for Sandy Bridge platforms.
It's about time, really. PCI Express has been around for several years now, and a move like this will give hardware developers the kick in the pants they need to fully transition to the faster bus interface. Most everything you need comes integrated nowadays anyway, everything from serviceable onboard RAID solutions to improved audio over year's past. Even dual-NIC ports are fairly commonplace on most modern motherboards.
In other words, this isn't anything to panic about, though it may mean ditching your old hardware -- like your PCI-based X-Fi card -- when it comes time to upgrade your system. The upshot here is that you should start seeing boards sporting more PCI-E ports than before, and who knows what unique designs mobo makers will come up with when no longer forced to relegate mobo real estate to PCI ports that few end up using anyway.
The death of the PCI bus only applies to the consumer side. Intel will still support the 32-bit interface on its enterprise-oriented Q67, Q65, and B65 chipsets.