I believe Hamilton is announced for 2017 - location to be determined. But, it could be the revamped Victoria Palace. A big show to be across from Wicked and to justify the expense?
I'm surprised there hasn't been any hints of School of Rock coming over, considering Sir Andrew is British, some would wonder why it opened on Broadway first! As for Hamilton, I doubt it will open in the West End. Only because of the whole rap and hip-hop vibe of it, I don't think a British audience could enjoy it as much as an American crowd.
School of Rock was announced for the Palladium in "Autumn 2016".
As for "Hamilton" - Book Of Mormon was thought to be too American, but is quite the hit. "In The Heights" was not on the West End, but I believe was quite the hit at Southwark and apparently transferred to Kings Cross and that transfer extended its run, so it must be doing well.
School of Rock is officially announced but I have heard it will shifting back to Spring 2017 to accommodate something else for Christmas.
As for Hamilton, In The Heights has shown that Lin-Manuel Miranda's music can get an audience in London and even without a British audience Hamilton will recoup on American tourists who can't get a ticket back home, similar to how Wicked was when it opened over here.