Nope.
Being sligthly faster (if you avoid updating to newer iOSs), sligthly thinner and having a sligthly better camera is not enough. Granted, I would rather have that than some pointless gimmicks like TouchID, but there isn't any real reason for me to update yet - the iPad Air won't do anything beyond what my iPad 3 does, as far as my needs go. If it were actually a better tool (sligthly bigger screen, flash) I would consider it.