So to get NetBSD including and running an up-to-date version of altq
using either ipf or pf, a few things seem to be required:

ALTQ needs to be api-enabled in a name-space-friendly and completely
segregated way:
    -Remove references to pf.conf and pfctl in favor of alt.conf and
altqctl (or netctl, or sysctl, or whatever)
    -Provide altq api for any packet filter to use mbuf tagging
Make packet filtering programs more portable:
    -Modify NetBSD's pf to use altq api instead of any built-in stuff
    -Modify NetBSD ipf to use altq api instead of whatever it's using now

Am I leaving anything out?