Confirmed by a recent Reddit AMA:

We will have some kind of sour out year round starting in 2014

I’m a huge fan of New Belgium’s sours, and I’m excited to see what, and how, they release a year round sour beer. More than likely, I think this may be referring to La Folie. Lauren Salazar has said before that she hopes to be able to release La Folie year round.

My other guess, is that it won’t be a 100% sour beer, and will instead be a blended beer; ie La Folie is 100% dark sour beer (Oscar) and Le Terrior is 100% light sour beer (Felix). A beer like Tart Lychee, on the other hand, is actually a blend of Felix with non-sour beer. This allows them to use less sour beer (an important consideration since it takes a year or two to sour a batch of beer), but it also makes the beer less sour. If it’s going to be available year-round, this will allow it to be more approachable for more people who don’t have the palate for a full blown sour beer.