"We are aware of and actively working on a fix for a bug that causes incorrect vibration notifications related to the Nearby Pokémon feature."
They're fixing the unnecessary vibratations bug that has crept in which is good as that was a little annoying yesterday.
The extra vibrations is draining my battery faster...
At least the Nearby feature is live in my region. Got a Dragonair just by following the dots to the Pokestop.