Chris Kapsambelis, of Barcode Data Systems, who has been a guest contributor here and is a regular commenter, has written an interesting piece published at AIDC100.org about barcodes and RFID being interchangeable.

He writes:

While DoD, Wal-Mart and others will undoubtedly demand their suppliers continue to tag pallets and cases with RFID, It appears that most users will have a choice as to which technology to use for Data Collection. Since items in the Supply Chain are being labeled with RFID, Barcode, or both, a user will be able to choose which manual data collection technology is more suitable. In the end, the choice between RFID and Barcode will be selected by popular demand.

Chris's earlier guest column here suggested that barcodes may be considered back-ups to rfid tags. See: Barcode to Backup RFID EPC Data.

While Wal-Mart and the Department of Defense do not appear to be backing off their RFID mandates, I do see a distinct sentiment developing suggesting that barcodes have a solid place and are not going away anytime soon -- whether as backups to RFID tags or as less expensive and less technology-intensive choices.