When the next version of the Forum module is released, will we be able to upgrade and maintain all of the user/post/thread information?  How will this look -- will we simply get the new features and stability without going through some migration progress?  Are there any issues we should be aware of, or simply do the module upgrade on our site?  (Assuming of course a recent backup just in case, etc).

Thanks in advance.

I agree with Matthias, you absolutely should backup your forum folder, bin, and the database at the very least. The actual upgrade process handles just about everything for you. After upgrading, however, all permission on the module will be dropped so you will have to edit the module settings and save them. NOTE: Do NOT give users Edit Module Permsisions in version 4.4.3 or greater of the forum module.

Just to be safe, however, I would also lock the forum down to admin only until you have a chance to review the permissions on every single forum, especially since so many options have been added. You should also double check the configuration settings in the various sections. Only other note that can be a 'gotcha' on upgrade is the theme is new and will break existing themes. You should switch to the default theme prior to allowing your users to use the module. Outside of this, its a pretty straight forward process that does take about thirty minutes to ensure a complete upgrade. I typically spend at least half this time on any module upgrade.