I also support SenderID.
I do not believe the IP issues regarding the PRA algorithm are
unsolvable; either the MS license can be changed to facilitate OSS
deployment, or a nonincumbered algorithm with similar effectiveness to
PRA can be found and substitiuted.
RFC-2822 authentication is my organization's primary need (and that of
our customers: banks). Sender ID solves this problem more neatly than
other solutions I have seen proposed in MARID. SPFv1 does not address
RFC-2822 authentication at all, and is therefore only marginally useful
to my organization.
Ryan Malayter
Bank Administration Institute
Chicago, Illinois, USA