Created attachment 408712 [details]
Description of problem:
This is surprising to me, although perhaps it is intended behavior. The following kickstart partitioning:
part /boot --size=200
part / --size=12000 --grow
part swap --recommended
on a system with more than one disk results in / being on different disk. Also present in RHEL 6 beta.
--grow without a maxSize tells kickstart to grow it as large as possible. Since there's more space on your second disk (what with /boot and swap being on the first), it prefers to move the / partition over to that disk.