Personally, I am thrilled with automatic app updates in iOS 7. This will ensure that bug fixes and other important updates get to as many users as possible. I always keep my apps up to date in iOS 6, but I know a lot of people don't. I have seen plenty of iPhones with a 14 badge on the App Store icon. This feature will easily solve that problem (it's on by default).
It does introduce another problem that will cause headaches for IT departments, though. What happens when an app that your organization uses dramatically changes (features, interface, etc) through an update without much warning? Evernote's version 5 update for iOS is a great example of what could happen. Imagine you are using an Evernote for Business account and you hadn't been paying much attention to the social chatter around the upcoming update. Update day rolls out and it's immediately on 300 iPads without warning. A teacher or student then opens up the app and EVERYTHING has changed. What happens then? There really is no recourse once it's done (without a lot of manual work). There is a setting to turn off these updates, but I've not heard if this can be controlled through Apple Configurator or MDM APIs. It's certainly possible that we will see that setting available on the release date of iOS 7. We already deal with this through Google Apps as the feature set and interface are tweaked on a regular basis. Everytime they make a change, I get multiple phone calls and emails asking about it. Hopefully, this is all solved through a simple MDM option.