If you have not yet bought tix, you may want to consider doing what I did...Buy your outbound now as a one-way and keep watching the fares for your return...I have been paying attention to the ticket prices for months and, based on my (very unscientific) observations, mostly using Bing, here is what i have found:
$400 or so RT for a flight with one stop is a good price
The lowest I have seen the nonstop flights is $511 Roundtrip
So, even if Bing predicts the prices will drop, I am doubtful that they will go much lower than $500 or so for the nonstop (although if you are willing to gambe and wait until a week or two before the trip you might get an amazing deal like $400 for the nonstops). Since the outbound is only $270 right now (on United on Friday the 4th or on Virgin America on Saturday the 5th) I went ahead and purchased it--knowing that it was near the low I have seen of $255 or so for the half of the RT nonstop.
Too much info?? LOL. I love thinking about vacation--it is fun for me to check the fares!