So... I've looked and looked for the answer to this question (I really have!!), I've tried a bunch of things, and I am very humbly asking for help from the smart people here.
I have a test version of my new writers' forums on one of my WP sites. I already know that I can migrate the forums themselves to a new site... (SimplePress)... but I have to migrate the users, too. I'm opening the test forums up only to a small number of potential mods and admins, but they will still lose all of their posts if I can't migrate them as users.
The closest thing I've been able to figure out so far is that the user migration actually happens through the host, which would be Dreamhost in this case. I've seen ideas about how to do it with other hosts, but I haven't been able to find out anything about exactly how it would work here. PLEASE PLEASE, any advice/help/thoughts would be so welcome!! I'm the only admin on this site right now, this is a real labor of love, I really need an EXPERT admin on that site but it isn't happening right now, so I have to do it... I would be eternally grateful for any help with the user migration issue.