Recent research showing that a section of the fault is long overdue for a major earthquake has some scientists saying the southern portion of the fault is capable of a magnitude 8.1 earthquake that could run 340 miles from Monterey County to the Salton Sea.
They're saying that a section which blocked the 1857 M7.9 earthquake, can no longer do so. That makes the possible rupture length jump from 200 to 340 miles. I don't think that really makes a big difference, but the article is going on and on about it. I still think the local M7's on blind thrust faults (like Kobe) are the bigger threat.