Today the Nexus team did an AMA on reddit. They tackled some difficult questions like "Why not include OIS?", and "Why No Qi Charging", but one of the most interesting answers was to the question "what does the X and P stand for?". As it turns out Hiroshi Lockheimer gives a pretty reasonable explanation. The X is in reference to the core of the neXus brand, and also just straight up sounded cool. The P simply stands for premium.
via Reddit