Gaelic is being revived. (Not that it ever actually died out, but it did get pretty well endangered.) The number of speakers have been growing steadily, and a new Gaelic-language school that opened in Edinburgh about two years ago was booked solid before it even opened.

Language revival is a slow process and takes a lot of teensy, tiny little steps! Though I suppose I should say this only applies to Gaelic in Scotland--Gaelic in Canada is still apparently doing fine. :)