Here is a nice article from the NOAA Northwest Fisheries Science Center that discusses the warm temperatures seen nearly along the entire eastern North Pacific Ocean:

http://www.nwfsc.noaa.gov/news/features/food_chain/index.cfm

I agree with their asessment that the cause is not straightforward at this time.  However, while we have not officially entered El Nino conditions at this point (ENSO depends on physics in/over the Pacific Ocean near the equator), it is not unusual for certain atmospheric and oceanic variables to behave "El Nino-like" prior to onset.  It is possible that warmer waters is consistent with the evolution *toward* El Nino, though the exceptionally above-average temperatures are certainly unusual and do not accompany every El Nino (or evolution toward El Nino).