Some of us are educators, and therefore, we do concern ourselves. Mispronunciation is not necessarily a pet peeve for me, just that I do know better, and so make a correction when called for. Hopefully, someone else (and they already have!) can correct me.
No, not regional slang or drawing out vowels, or anything like that.
There's been a push lately (it seems) that the pronunciation of towns and places have accepted changes, too.