Hmmm, interesting but if they (and so far they are) keeping with the more old school angel mythology, then angels are people and people aren't angels. There are angel/human hybrids (damn if I can remember the names of them) but they're always girls, always horribly disabled, and almost always die in their teens (aka assumed into heaven to become angels.)

Of course, they could change this, there's a lot of angel mythology out there, but so far they're keeping with the old school lot.