CritiqueBrainz should be more visible from MusicBrainz. I think we could start by displaying information on release group pages, such as how many existing reviews there are, an extract of one or two reviews (the most recent and the most highly voted would make sense) and a link to write your own review.

Until we have something like MBS-7722, we could fetch the data from the CritiqueBrainz API. There was some discussion about how that should work at http://chatlogs.musicbrainz.org/musicbrainz-devel/2014/2014-09/2014-09-10.html#T12-46-16-281466