So heres one big thing, they won't charge you $160 outright, it's a monthly bill that goes to your credit card. You need to be eligible for this (aka i mean you need to be in the u.s., canada, singapore, australia, new zealand).
Here's a quick image of you should expect from getting the annual pass..
You can pay for the WoW Annual Pass on a monthly basis at $14.99 per month or according to the billing plan of your choice. To participate, you must be 18 or older, have a valid credit card, and have registered a full version of World of Warcraft on or before October 18, 2011.
Sign up for the World of Warcraft Annual Pass here, and then keep an eye on the World of Warcraft community site or the Diablo III community site for future announcements regarding the launch dates of these bonuses.
Here's the Youtube Video..in case you missed it.