The Mac App Store
Like the existing App Store for iOS devices, Apple's announced Mac App Store will offer one-click downloads and installation, and licensing will apply to all Macs that a user owns (though I can't help but wonder if there will be a limit). Developers whose software is sold through the Mac App Store will receive the same 70/30 revenue split as with the iOS App Store. Although touted as a feature of Lion, Apple has promised that the Mac App Store will launch within 90 days.
It isn't surprising that Apple would choose to introduce the App Store concept for Mac software. The model has done well for Apple, and the company borrowed from it in designing its Safari Extensions Gallery. Apple has also maintained a library of information about Mac software on its Web site for years now.
This model makes sense for end users too because it simplifies the purchase and installation process: No waiting for a store to open or a package to be delivered, and no relying on installation media or having to delete .DMG files (the most common download format for Mac software) after installation. It also makes it a lot easier to maintain updates.
The Mac App Store may also help smaller developers get noticed. It's hard not to assume Apple has been planning the Mac App Store for quite some time and that it was part of the reason for dropping the price on the Mac developer program membership.
On the plus side, the Mac App Store will not be the only option for finding and purchasing Mac software. I think this was one of the biggest concerns that Mac users and developers might have had over the concept. Downloads from the Web and traditional installation media will remain supported. From the demo today, it looks as if both iPad-style full-screen apps as well as more traditional applications will be supported.
There are, however, a couple of major concerns that I have about introducing this model:
Will users be forced to upgrade or be able to downgrade applications? This is a problem with the iOS App Store. Once an update is downloaded/installed, it can't be reverted to an earlier release, as you can if you have the install media or original installer files of a desktop application. Several iOS app updates have introduced bugs or performance problems; when this occurs, there's no option but to wait for a developer to fix it. With the more complex environment of full-fledged computers with specific configurations and peripherals, testing for across-the-board compatibility would be largely impossible.
What about volume and site licensing? The App Store approach is great for home users, but I can't see it playing out well in schools or businesses where a base configuration and set of apps needs to be made available to a large number of computers. This is already a challenge when deploying iPhones and iPads in bulk, and has been since the App Store launched over two years ago. While iOS 4 addressed many enterprise concerns, it left a gaping hole in terms of mass deployment of apps. Apple could resolve this challenge by including an app management and license server feature in Lion Server.
Auto-save and auto-resume
I like the concept of Apple building the ability to auto-save files into Lion so that every developer can easily include it in their applications -- so long as it doesn't lead to file system challenges like those on iOS devices (where there is no central access to a file system) and it doesn't mean that traditional Open and Save dialogs and methods are going away (which I doubt). Let's face it; we've all lost work because we forgot to hit Save often enough, so this is a big plus.
It would be nice to see this feature tied into some form of revision history. I'm thinking particularly about the ability of Google Docs and Dropbox to find previous versions of a file if you decide you don't want to keep the changes that you (or someone else) made to it. Given that this feature exists in a somewhat limited form with Apple's Time Machine, I don't see it being a big challenge to create, and it is a natural extension of the auto-save concept.
Auto-resume is something I'm less enthusiastic about. It works well for mobile devices that display only one application at a time because you have to switch in and out of apps frequently. I'm not sure I want or need that in my desktop apps. Most of the time when I launch Word, for example, I want to start a new document rather than automatically seeing the last document I had open; otherwise I'd have double-clicked the document I wanted. So I'm hoping this will be an optional feature that users can enable or disable as whole or, better yet, on an app-specific basis.