After Apple's latest event and unveiling of a Mac App Store that promises to make Macs very iPad-like indeed, it seems that a lot of people are smelling something very Orwellian afoot. While the idea of an app monoculture does seem to be gaining ground, especially in light of the success of the App Store on iPads and iPhones/Touches, there are a number of good reasons why the Mac's App Store won't be the only software gateway onto Macs--although it does seem like it's only the beginning of Macs and iOS devices growing ever-closer together.
Self-made software. If Macs are like trucks, then we need to be able to do our own work on their engines. For those who program, make their own software, or distribute tools and software suites in their own office environments, labs, or development studios, an App store which requires Apple approval is absurdly useless. Plain, old self-installation is the way to go.
Big-ticket software. Movie production software, $60 games, and other products that can cost hundreds of dollars seem like unlikely fits, simply because people prefer backup discs and the high cost of the programs mean Apple would take a huge cut of the profits. This might change in years to come, but for now those pricey suites will probably continue to come directly from the manufacturers.
Consumers won't have it. Sure, Steve Jobs calls the shots, but a completely closed-off OS is the stuff of midnight scary blog posts. Apple's iOS is closed and gets away with it because these products are consumer devices that few people program on, and no one ever experienced them as open. If Macs were closed, more people would choose Windows PCs, and sales would suffer.
Apple doesn't need to close off the Mac to succeed with the App Store. If Mac apps are easy to find, affordably priced, and are easy to update--and come vetted from Apple--the majority of consumers will choose to go through the App Store for mass-market software when possible. Closing off the Mac to other methods of software installation simply won't be necessary for the App Store to succeed wildly...it'll just be the back-door way of doing things versus shopping at the shiny clean mall.
It will be a fun way to find middleware. It's hard to track down good independent software programs on the Mac, short of taking blog and friend recommendations. An App Store will allow a lot of one- and two-man teams to sell their software very quickly, and while Apple will still have the right to accept or reject any app, it should be an additional avenue for discovery at first rather than an overbearing burden. When the App Store opens in 90 days, it will be just another way to get software on a Mac. It'll also be the most compelling one.