While the tropical Pacific Ocean surface temperature is currently at levels typically associated with a weak El Niño, waters below the surface have cooled and atmospheric patterns continue to remain neutral.
However, over the past fortnight changes have occurred in the atmosphere that may be a response to the warm surface waters–the Southern Oscillation Index has dropped by over 10 points, and weakened trade winds have re-appeared. These changes would need to persist for several weeks in order for an El Niño to be considered established, and it remains possible they are simply related to shorter term weather variability.
Climate models surveyed by the Bureau continue to indicate that El Niño is likely to develop by spring 2014. The Bureau's ENSO Tracker remains at El Niño ALERT, indicating at least a 70% chance of El Niño developing in 2014.
Here's an animation comparing sub-surface temperatures from January to April this year with those of March to June. Note the two-month overlap.
Dan Satterfield has a short article in which he raises some points worth noting, particularly if you live in the USA.
For other references, I've included some good ones in an article about ENSO, which I wrote some time ago. (Yes, I'm being lazy.)