Status of Email Authentication

Seems like email authentication may be stalled because not enough ISPs are 
actually using it.  They won't start using it until can help them filter 
incoming spam.  That won't happen until a lot more other ISPs are using it, 
and there are some good domain-rating lists available.  Vicious 
circle.  Guess we'll have to wait for Microsoft to get the ball rolling.
I've done two things.
1) Written an encyclopedia article to explain the basics of email 
authentication, independent of any particular method.
2) Offered to help my ISP set up a test platform, and see if authentication 
can help in filtering the incoming flood.
I would like to get comments on the article 
http://en.wikipedia.org/wiki/Email_Authentication  I'm especially concerned 
about the section on email forwarders.  I had to take a wild guess as to 
what an eventual standard header might look like.  Does anyone know if 
there has been any progress on this?  I saw a recent article in CircleID 
about IETF http://www.circleid.com/channel/index/C0_6_1/ .  If anyone can 
get beyond the arguments over petty details, it will be IETF.
As for the test platform, I'm looking at using Sendmail.  They seem to be 
the most aware of the huge potential payoff for authentication, and the 
various factors needed to get things started.  They are supporting all 
three methods ( SPF, SenderID, and DomainKeys) 
http://www.sendmail.com/solutions/security/  although they state in their 
FAQ that a cryptographic method will be the best long-term 
solution.  http://www.sendmail.com/solutions/senderauth/faq/#difference 
"Sendmail strongly believes that cryptographic approaches are the right 
long term solution as they avoid many of the infrastructure disruptions 
that IP auth would cause and they offer strong protection of the message 
contents themselves."  I guess that means DomainKeys.
Are there any other MTA's besides Sendmail that I should look at for the 
tests?  Does anyone have a suggestion for a domain-rating list?  I see 
SpamCop.net has a nice blacklist, and SenderBase.org has good statistics on 
total mail volume.  Seems like a good starting list could be generated 
using ratios of spam reports to total volume.
-- Dave