Socket AM3 and AM2+ compatible
The first Deneb, 45nm quad-core Phenoms with a total of 8MB cache, will launch in January at CES, but the real McCoy will launch roughly one month later. The Deneb coming in January is a socket AM2+ processor, while the socket AM3 with DDR3 support will come in February.
These CPUs will work in both AM2+ and AM3 boards as they have a combo memory controller that can support both memory standards. AM3 motherboards are expected at the same time and since the memory controller is on the CPU, the existing chipsets can support it, as long as the motherboard manufacturers make the board with a DDR3 layout.
It definitely looks like AMD is coming back with its quad and tri-core 45nm products, followed with Deneb without L3 cache codenamed Propus. The only thing that AMD will miss is a dual-core based on the K10 architecture.