Various Wikipedia's do have what you are imagining.[0] People are not normally automatically given the right to review changes and even if you do manage to review malicious edits they are easily reverted by others.

Every language has their own policies, but the English Wikipedia only has it enabled on certain pages.[1]

[0] http://meta.wikimedia.org/wiki/Flagged_Revisions

[1] http://en.wikipedia.org/wiki/Special:StablePages