I'm pretty sure that apple will be offering big players a better revshare deal on account of their volume. I'm sure their respective legal departments will have their hands full in the coming months. I think what is more interesting is what will happen to new apps built on the app store which subsequently become big; apple will have no incentive to split the revenue more favourably when they already have lock-in.

Regardless, I'm a fan.

The big players have their own licensing systems, and have their own licensing deals with big customers. I don't see why they'd go through Apple. They don't need help with collecting payments, or file distribution, or bandwidth.

No one really says they have to. As Jobs said it won't be the only way to get Apps. But smaller devs benefit greatly. You can go from 0 to collecting payments worldwide, having distribution, updates, a 'store' to display your product, etc. with very little work (in comparison to doing it all yourself).