Proper procedure to update hal on -current

Hi,

Given:
http://lists.freebsd.org/pipermail/freebsd-current/2009-March/004871.html

and the fact that I've got devel/libusb deps forced on me (x11/kdebase4-
workspace for example), what would be the proper procedure to upgrade HAL. 
Right now I'm using a +IGNOREME with portmaster, but I'm sure this will break 
stuff in the not so far future.

Do I need to temporarily uninstall devel/libusb (it doesn't build now anyway, 
but maybe upgrading to today's current will fix that) then reinstall it?

Any chance some BROKEN vars can be set based on FreeBSD_Version?
-- 
Mel