For the latter, the Santa Clara, California-based CPU maker will offer Pentium 4 “Northwood” 3.40GHz processors with 512KB L2 cache and 800MHz Quad Pumped Bus as well as Pentium 4 “Prescott” 3.40GHz processors with 1MB L2 and 800MHz PSB.Source: X-Bit Labs
It is not fully clear why Intel decided to cancel 478-pin Pentium 4 “Prescott” processors 3.60GHz provided that some mainboards were capable of supporting the chip which dissipates up to 103W of heat.
According to certain estimations, there will be 8%, 32% and 45% of LGA775 processors in Intel’s desktop lineup in Q2, Q3 and Q4 respectively. Obviously, a substantial part of such chips will be top-end Pentium 4 processors at first.
"Intel's Socket 478 to be dead at 3.40GHz"

While Intel originally planned to release 3.60GHz Socket 478 CPUs this now seems to be untrue according to some sources. They claim that the last Socket 478 processor from Intel will be a 3.40GHz model with 1MB or 512KB L2 cache. Everything starting from 3.60GHz will be only available in a LGA775 package.