Revisionary

Revisionary allows rights to view and revert revisions to be controlled on a per-content type basis. The most common use for this is to provide wiki-like functionality for specific content types mixed in with a larger site, without giving a broad user base rights to view revisions on all content types.

After installing, go to admin/settings/revisionary and choose your content types. Any user with rights to edit those content types will now be able to view and revert revisions on them as well. Revision deletion rights stay with the administer nodes permission.

There are a few modules which use node_access to do something similar, but you quickly run into the multiple node_access patch issue. This module does not rely on node_access so should be usable on sites running OG, Domain Access, or the like.