The fastest chip is the Athlon X4 605e, this Propus-based quad-core without L3 cache will have a frequency of 2.5GHz and 2MB of L2 cache. It has a 65W TDP and will arrive in late Q1 or early Q2 2009.
There will also be a quad-core Athlon X4 6xxe clocked between 2.1GHz and 2.4GHz, this will be AMD's first quad-core chip with a 45W TDP. You can expect this chip in May 2009.
Then there are also two triple-core processors based on the Rana core, these chips also lack L3 cache. The Athlon X3 405e is expected to have a frequency of 2.5GHz, and a 65W TDP. You can expect it in early Q2 2009.
Another triple-core chip is the Athlon X3 4xxe, it will have a frequency between 2.1GHz and 2.4Ghz, and 1.5MB L2 cache. This CPU has a 45W TDP and is expected in mid-Q2 2009.