Looks like Apple just (NOT) gave developers control over update release dates!
Update: Nope, didn’t work. Sorry for the false positive folks.
With the recent changes in iTunes Connect, where the application name, keywords and rating can only be changed when submitting a new binary, it looks like Apple have properly separated the Update of an app from the Live version.
Before, if you were editing details on the Update, it would directly affect the live information, including taking your live app offline if you set a release date in the future for your update. As pointed out by furbo.org among others, this meant you had no control over the release date of an update to your app, and it was hard to time updates of for example server side components of an app.
With the recent changes to iTunes Connect, I was curious to find out of the separation of Updates from Live apps also meant that the release date was separated, since we’ve sorely missed this feature on a number of occations at RjDj. So we gave it a try with one of the RjDj apps: RjDj Shake. Risking to take it offline briefly to find out, I changed the release date for the update we submitted today to Aug 10 2009, and hit Save.

After 15 min, the live RjDj Shake is still in the store, and changes we’ve made previously have come though in the live store quicker than that. Looks like a win to me. :) Happy release planning, folks! Can anyone else confirm this find?

