Current status - Pending changes (level 1) was re-enabled on December 1st, 2012 by community consensus according to the 2012 RFC.
Logged in users – Logged in users (or users choosing to view pending changes) will see all edits as usual (unless the relevant setting has been changed in their preferences). All edits will still be added to the wiki and inappropriate edits must still be reverted or fixed as usual.
Logged out users – Until checked for obvious vandalism or superseded by appropriate editing, edits by new and unregistered users to "pending changes protected" pages will not be seen by users who are not logged in until approved. Edits by autoconfirmed users are approved automatically at level 1 when the prior revision is approved.