The dual-core 2.66GHz/3.33GHz i5-580M will be situated between the 2.8GHz/3.46GHz i7-640M and the 2.66GHz/3.2GHz i5-560M. It's interesting that the 580M and 560M feature the same base clock frequency, instead varying in peak Turbo Boost speeds. All of those chips consume a max of 35W and should roll out in the fourth quarter of this year.
Stepping down the thermal ladder, Intel will launch the 25W 2.26GHz i7-660LM, 15W 1.46GHz/2.53GHz i7-680UM, and the 15W 1.33GHz/2.13GHz i5-560UM. Naturally, all the dual-core CPUs will have an integrated Intel HD graphics core.
At some point early next year, Huron River will debut, bringing a significant boost in processor and graphics performance, WiMAX, WiDi and Intel Bluetooth, not to mention power savings substantial enough to play two Blu-ray movies on a single charge.