AnandTech stumbled upon a week-old roadmap from ATi and published all the information in a nice article.
ATI's entire roadmap revolves around the transition to PCI Express, which ATI is particularly happy with since they will be providing native PCI Express GPUs from the get-go. The difference between a native PCI Express GPU and a "bridge" solution is that the latter has a little translator that takes PCI Express interface commands and converts them to AGP interface commands which are then sent off to the GPU. Obviously a bridge solution isn't very elegant and it isn't desirable from any standpoint other than a time-to-market one as it's always quicker and easier to have one GPU that can talk to any interface. Eventually no GPUs will have this silly PCI Express bridge, but at the start ATI is happy to announce that all of their GPUs will be "bridge-free."
In order to accomplish a bridge-free roadmap, ATI has to have two versions of every GPU: a PCIe and an AGP version (or an AGP substitute). Keep this in mind as we look at the GPUs due out in '04 since you'll be seeing two per market segment, one AGP and one PCIe.
It's also worth noting that all of ATI's GPUs will be available in both PCIe and AGP flavors throughout 2004.