Aside from all the new features that 4.1.0 betas introduced, this release includes over 80 bug fixes, resolving issues discovered in the last round and during our continuous internal code review process.
XenForo 2.2.x Compatibility
While we were wrapping up this release, XenForo 2.2.x Betas became public, and we learned that previous versions of VaultWiki would not run on those versions without encountering fatal errors and other showstopper issues. So we took some additional time to ensure that VaultWiki 4.1.0 would run under those new XenForo 2.2.x versions.Thus, VaultWiki 4.1.0 is the first version that will run on XenForo 2.2.x. However, please note that we have not implemented any new XenForo 2.2.x features at this time.
Looking Ahead
Over the coming months, our main focus will be migrating this site to XenForo 2. In addition to the normal forum, wiki, and other add-ons, there is a significant amount of in-house code that has to be rewritten for XenForo 2. So the migration will occur as soon as it is feasible.At the same time, main development now turns to the next feature branch of VaultWiki. For the life of 4.1.x, we expect future releases to mainly be for maintenance; that is, bug fixes or fixing style issues.
As mentioned elsewhere, there will be no further releases in the 4.0.x series, except security patches for the rest of its supported life, which is roughly 6 months from the time of writing. If you are still running 4.0.x, you should endeavor to upgrade before that time.
VaultWiki 4.1.x will be the last series to support vBulletin 3.x, vBulletin 4.0.x-4.1.x, XenForo 1.x, and XenForo 2.0.x. While there is plenty of life left for this branch, please be aware that you should aim to upgrade your forum to a newer version at some point, or you may find yourself unable to upgrade to the next branch.