Compatibility with 3.6
Currently, it would seem that a large portion of vBulletin sites (40-45%) are still running vBulletin 3.6.x. VaultWiki compatibility starts at 3.7.x, so we're missing out on a significant portion of the market.
We should spend a few days making VaultWiki vBulletin 3.6.x degradable. Some features would be missing, but otherwise the product would be installable in the majority of existing boards.