It is a hotfix just to fix the WPA issue. BETA/Hotfix firmware will need to go through official testing and may need to pass all the global certification (FCC, etc) before considered an "official" release. Lots of hoops for an official release but in most cases the firmware file never changes from the beta/hotfix.
Hotfix = A specific feature addition/fix or security patch (very minor change)
BETA = A bunch of fixes and changes, possible feature additions or deletions (major changes)