Yep, it's hidden deep, but it's here! For folks like me who keep the phone on silent at all times, it sure would be nice to know who's calling without pulling the phone out of the pocket. Presenting custom vibration patterns for callers!
Even better, not just content to give a set of predefined patterns, you can compose your own! Very cool. Extra points to the bling of using the flash as a notifier, optionally.
Funny, I heard absolutely no mention of this feature; guess Apple didn't want to...ahem...shake things up?