VZW is notoriously slow in pushing updates. I wouldn't expect them to finish pushing this to everyone for 4-6 weeks. FWIW, I work in an office of 30 people and everyone was issued a Droid 4, and only 2 of us have ICS. And we both manually forced the update.
Interesting. Things must have changed since the days when I had my Droid 2. I almost always got my update within a day or two of it being released. Going 4+ days without it being released was unheard of. You'd think with LTE they'd be able to push it out faster than in the 3G days.