Actually Wal-Mart, Barnes & Nobles and other stores that carry CDs are carrying several of the single inventory, SACD only releases.
These include the 22 Rolling Stones Remastered SACDs, the new Dark Side of the Moon SACD by Pink Floyd and The Hits by The Police.
The new 2-SACD set "Rendezvous in New York" by Chick Corea has also been spotted on sale at 10% off this week at Barnes and Nobles stores.
So if it's an SACD only release, you will indeed find it in places that do not carry the dual inventory SACDs. A very encouraging trend!