Examples of pronunciation changing over time include words like "controversy" - once pronounced as "conTROVersy", now pronounced as "CONtroVERSy".

The opening credits of the BBC2 "Eggheads" programme describe the resident team as "forMIDable", whereas, as any properly brought up chap knows, it should be "FORMidable".

As for usage, let's enjoy "to critique" - an ugly back-formation if ever there was one - long used in university committees! And if I ever hear "decimate" used to describe the destruction of more than 1/10th of anything ever again...

C'est la vie.