You think just because they offer a third party way of getting the app and doing in app payments they need to leave the app store?
No, I don't think they need to leave the Apple app store, I believe they will, see post #49.
You assume they would do this
Again, detailed my thoughts on why major devs will leave the app store in post #49.
I would assume most wouldn't because of the reach the app store has and people not trusting 3rd party app stores and not wanting to lose customers like you. My assumption is they would just up charge on the apple app store to offset the apple commission. Not sure why this is hard to understand.
How much of a savings to you believe a dev will realize if they leave the Apple App store and go it alone, 5%, 10%, 15%? Please note that the dev will need to host a web site capable of supporting login accounts for purchase/updates, market their own app, provide customer service and payment processing. Please be specific.
If devs are allowed to keep an app on the Apple App store and allowed to advertise the fact that consumers can purchase it as a substantial discount on the devs site then I have a problem with that as the dev is using Apple's App store as a "free" marketing tool to direct consumers elsewhere. This would be equivalent to having your product on the shelves of Best Buy but putting on the box "you can save 10% by buying this product on our web site".
I could care less about alt-stores / alt-payments if:
1) All apps must be available on the Apple App store and available from Apple's payment system in addition to any other store the dev wants but at either the same price or a reasonable premium, say 10%. No one will convince me that devs will not incur at least 20% cost for providing the same services that Apple gives them via the store. No listing an app for .99 on your indie site and $99 on the Apple store just to force traffic to your site.