EVGA is joining a number of other manufacturers and is also releasing a number of its graphics cards in versions with double-BIOS. Not only this, but three of its cards actually have three BIOSes rather than one (or two).
While users with fairly basic needs might not see the advantages, overclockers should definitely be interested in the feature. It allows you to have one BIOS set to stock settings as a failsafe, and use the secondary BIOS as an overclocking BIOS. It also allows you to experiment with installing custom BIOSes but without risking the card getting bricked due to a BIOS or flashing failure.
For the entire list of double-BIOS SKUs from EVGA, head to this list.