AMD's RX780 chipset, a cut-down version of the similarly AMD-oriented RD790, has won the approval of the PCI SIG, the organisation behind the PCI Express standard. So has a reference motherboard. Both certifications are key steps towards the release of the product.
The RX780 closely matches the RD790's spec, just losing one of the latter's two PCI Express (PCIe) x16 slots. It supports HyperTransport 3 and Socket AM2+ and will be paired on motherboards with AMD's SB600 southbridge chip.
Roadmaps that leaked out in March this year didn't include the RX780 - the closest they got was the RX740 and the RS780.
The latter's a DirectX 10-supporting integrated chipset due next year and set to be partnered with the upcoming SB700 southbridge. The RX740 was described as a single PCIe x16 board, but one supporting PCIe 2.0.
At this stage, it's not known whether the RX780 has replaced the RX740, or will be offered by AMD alongside it. RD790 was not described as a PCIe 2.0 part, so it's likely AMD is offering two RX chipsets :one with PCIe 2.0 support, one without but both with a single PCIe x16 slot.