You're right, except the part about package managers. This is one of those things that Steve Jobs' quote about "People don't know what they want until you show

You're right, except the part about package managers. This is one of those things that Steve Jobs' quote about "People don't know what they want until you show it to them" applies. People will LOVE the app store on OS X. For all intents and purposes, the iTunes app store is already evidence of that. It doesn't have to be perfect, it just has to be easier to use than whatever we have now. And what we have now isn't as usable as an app store (or "package manager").