Long tail at Google is not working the way it used to ~ by accident or by design.
But was this really caused by Panda, or was this caused by MayDay, and amplified by Scraper and Panda updates(which most people who have analyzed think have given a boost to "authority" in the SERPs), and exacerbated by autosuggest?
Matt Cutts said the MayDay update was squarely designed at making it harder for sites to rank for the longtail. Do we have a handle yet on what was changed for MayDay? It's been a year on now, and if we still aren't sure what changed then, it means it could be a year or more before people figure out what really changed in Panda.