The world will shift dramatically for Mac software makers at some point over the next 90 days. That's the time frame Apple has given for launching an app store for Mac software not unlike the hugely successful App Store for iOS offerings.

The announcement, which came Wednesday during Steve Jobs's preview of Mac OS X Lion, had been rumored for some time, though it was hard to get a grip on just how Apple might port the iOS app distribution model to the Mac. Now that the cat is out of the bag, though, there are a number of arguments to be made for and against Apple's latest App Store effort.

Let's start with what we know. The Mac App Store is slated to launch in the next 90 days and will be available at least initially only to users running Mac OS X 10.6. Developers can apply for the app store starting next month. On Wednesday, Jobs said that developers will get the same revenue split Apple offers to iOS-app makers: 70 percent of the revenue, with Apple pocketing the remainder.

In exchange, developers will need to abide by rules similar to those that govern the App Store on iOS, including restrictions on what kinds of content can be published, agreeing to use only officially sanctioned programming interfaces and submitting software through an official app review and approval process. On Apple's mobile platform, these processes have at times been contentious in nature, with a few developers pulling out of iPhone development altogether over Apple's vetting policies.

From a consumer's perspective, the App Store is probably the most revolutionary announcement that Apple has made in a long time, my colleague Dan Frakes has written an article on the many benefits that users will derive from a Mac App Store. From the point of view of developers, however, things are a little more complicated.

Despite its limitations, the iOS App Store is successful with developers, in part because it doesn't play favourites, classics such as Bejeweled and Tetris are listed right alongside complete newcomers who have no affiliation with large software publishing houses. In fact, as I write this, seven out of the top ten bestselling iPhone apps have been produced by small and independent vendors that would find it difficult to make a dent in the traditional software market.

Today's OS X software market is rich with applications from smaller developers, you could argue that these programs form the very backbone of the platform's software ecosystem. Still, each of these independent vendors is forced to implement their own payment solution, licensing management system, distribution channel and customer support, leading to inconsistencies and duplication of efforts.