...given the fact that BJ's will, very soon, be selling themselves to private investors, we can count on quite a few store closures -- this is usually how things play-out when retail companies go downhill (which has played itself out repeatedly in South Jersey with names like Jamesway, Caldor, Bradlees, and Ames all disappearing from the retail landscape).
Best I can guess is that since BJ's has not expanded beyond the east coast, that will be their big weakness. The other two U.S. warehouse clubs (Costco Wholesale and Sam's Club) are global operations.
Speaking of Sam's Club, it is noteworthy to mention they are part of the Wal-Mart empire, which means (like 'em or hate 'em), they have the financial security to serve their club members for many years to come...