PCI express.. next generation cards?
what will happen to AGP slot?
PCI express will replace both PCI and AGP.
The parallel PCI bus is an 10 year old technology (that is a very long time in the computer world) that somehow stuck. It is actually the bottleneck speedwise in modern computers: chip producers (Intel) are delaying the release of their next generation chips (4GHz+) since it makes no sense increasing the chip speed if the PCI bus is the actual limit. I guess the same applies to those who make graphic cards.
Intel and Nvidia are collaborating for the next generation graphic cards, which will likely use PCIExpress X 16 which can reach an 8 Gigabyte bandwith.