According to Chinese-language site HKEPC (via Register Hardware), AMD is slated to debut Socket AM3 Phenom CPUs during Q1 09.
According to a roadmap leaked earlier this month, AMD will release their first desktop CPUs based on 45nm architecture (codenamed "Deneb") for the AM2+ socket some time during Q4 08. These AM2+ CPUs will be rated at 125W TDP. If this latest information is correct the AM2+ models will be quickly followed by 95W TDP AM3 models rated at 2.4 to 2.6GHz and 2.5 to 2.8GHz. These will both have 2MB of L2 cache and 6MB of L3.
During Q1 09 we can also expect to see the release of "Propus" quad-core Socket AM3 Phenom processors. These will run at 2.4 to 2.6GHz and 2.5 to 2.8GHz and be rated at 95W TDP. These processors will differ from other Phenom processors in that they do not feature an L3 cache (current Phenoms X3 and X4 have 2MB of L3 cache shared between all cores).
It seems that AMD is enthusiastically embracing AM3, the main feature of which is that it adds DDR 3 memory support. It should be noted that AMD has previously said that while Socket AM3 processors will work in Socket AM2/AM2+ motherboards, not all AM2/AM2+ processors will be supported by AM3 motherboards. By this time the price of DDR3 RAM might have fallen to a point where it's affordable.