An Example of Agile Methodology, with a bit of a struggle

We are in the process of re-designing our website launch. The site will be based on Wordpress CMS, new content, new functionality, some revised branding, and new layouts. It's been a long time coming. I've been trying to think of an approach to launch the website iteratively so that its not contingent on a Big Bang launch and dependent on everything being done to launch. Unfortunately, I keep circling back to thinking that a partial launch of the site would diminsh our brand due to limiting the user experience. Therefore, I am currently aimng to launch with most of the requirements we've laid out for this project and not launch iteratively. Granted, some requirements can be de-prioritized for a future release, but the baseline site ("product") needs to be all (most all) or nothing for now. Now, this can all be bundled into a "Release", and requirements ("User Stories") tackled in a Sprint like fashion, but ultimately the struggle was in producing a finished product within a Sprint...that I didn't feel comfortable with, as we only have 5-7 seconds to grab a User's attention on your site, and a site that isn't 100% ready would lose the user pretty quickly. So, a bit of a struggle on applying Agile principles to a Released product in this situation.