It is available in physical form- I myself have a copy. However, I ordered mine online- local stores have to order it for their own shelves as they order anything else. Your LGS may not be psionics-F without you to ask them to stock it (or special-order it for you).
However, on a related topic, I'm wondering when my order (through Paizo) of a paperback Psionics Expanded will be filled- it's been over a month since I preordered it, and AFAIK Dreamscarred are selling it through their own website- what about those of us who ordered it through other game outlets?