I just looked over the sshd 4.9 release notes, and came across this gem:
* Added chroot(2) support for sshd(8), controlled by a new option "ChrootDirectory". Please refer to sshd_config(5) for details, and please use this feature carefully. (bz#177 bz#1352)
This is awesome, and should negate the need to use pam_chroot! Nice!