We're hoping to have 1.2 running here on XenForo.com in early June. The initial beta release will follow, based on how well the time on 1.2 goes. The final release of 1.2 would be wholly dependent on how the beta process goes.
I recall Mike mentioning 'early June' for the beta, so that would narrow it down to probably 1st - 15th. Beyond that we'll just have to wait, then hope that there's not too much to change in the beta before the final release.
I can't see how anyone would know other that staff and Mike , even then there may be unforeseen issues that may occur like the tags exploding, Redactor lens flaring up and causing blindness, there's just so many factors. But June 8th is when it may be appearing on the community forums but they may have to control redactors reactor from overheating and may be still working on the editor in keeping it cooled to a comfortable -15 degrees C.