I figured if Buffy had actually killed the First that maybe there would have been a next in line to succeed it. Kinda like the slayer line... only big baddish. Although this idea kinda remins of "the source" on Charmed whom was succeded by several individuals, which in the end got kinda cheesy and disenchanting. I mean you get used to one omnipitent evil that has always and will always have the power. When This power can be destroyed and passed on to others it kind of loses it's edge. It makes it seem weak and frail which is not what the forces of evil have ever been about. They boast power, corruption and an overall dark design for the world. Probably if someone had taken over for the First I wqould have been disappointed at how easily it was destroyed. So in conclusion good job team whedon for not killing off the ultimate evil and dissapointing a loyal fan. Hopefully it'll show up in Angel. Would be a nice little crossover.