If JBLU is willing to cough up $15M for an ad campaign at this time, I can only guess for two reasons
1. Shift of low-cost carrier model to a premium airline (thus abandoning low cost and low price strategy) - that part makes sense. However, the whole image is still very leisure pax oriented, and bears similarity to what Virgin does.
2. Prepping itself for an alliance with another carrier, Lufthansa? Virgin?