Warner Home Video has hired the services of the company Prime Focus London to convert two back titles in the
Harry Potter series for 3D Blu-ray:
Harry Potter and the Order of the Phoenix and
Harry Potter and the Half-Blood Prince; work has reportedly already begun on the latter. The studio has not revealed whether those two will get a theatrical re-release in 3D, or when the 3D BDs are expected to come out.
WHV hasn't made public plans regarding 3D conversions of the first four Potter movies, but their conversion also seems likely.
Prime Focus was criticized because of the poor quality of the 3D conversion of
Clash of the Titans. Afterwards, the company refocused on higher quality and has ostensibly been avoiding rush jobs.