Good question, Brian. The dry conditions over Arizona this winter are consistent with the expected La Nina influence, so I suspect that La Nina has been a factor. As we transition to the warm season, however, precipitation over Arizona generally will be associated with the North American monsoon. As Emily wrote a few years ago, we don't see a very strong relationship between ENSO and the North American monsoon, so I cannot say that ENSO neutral conditions will make it much more or less likely that the drought will start to break. ENSO will have a bigger influence on Southwest precipitation next winter, and it's too early to say whether or not La Nina will return. 

As a general reminder, you can find CPC's seasonal outlooks at this site, which will include the influence of ENSO and all other factors that could influence seasonal temperature and precipitation.