The newest update came out yesterday and renders this whole discussion moot. A whole host of updates relating to EAS have been impemented see here:
Palm Support : Palm Pre Sprint - Software update information for Palm Pre Sprint p100eww
In particular this quote:
"Support for self-signed certificates with multiple common names has been added."
So now the Exchange server I was working with, with Self signed certs.. synced up first time. As long as we're here, these are the specs you need to input. Make sure you running at least WebOS 1.10 (as of the writing of this post)
1) Load the server's web cert by saving it from the website where one would access OWA. Then copy the cert file through a USB connection, email it to your self then install the cert directly into the Certificate Manager. Or you can go the OWA site and authenticate the certificate from there, that installs the cert into the Certificate manager also.
2.Account settings:
email address: just like it sounds
User Name: just the user name part of the email address
Password: you know the "password"
Mail server: use the FQDN mail server name: ie mail.mydomain.com
Domain name: use the internal FQDM ie mydomain.local your full servers name is pobably server.mydomain.local
Then sync! worked form me first time! (that is first time after the latest update)
Mark