When Apple said they were introducing an "App Store" to OSX a-la the iPhone, iPad, etc. there was much ranting and foaming at the mouth...Many geeks proclaimed the death of Mac OS X as we know it. "Apple is iPhone-izing the Mac!" they cried.
They're largely wrong, at least in all the important ways.
Here are the salient points:
Discovery - people are *far* more likely to purchase things that are available from a single, readily accessible source. Having a veritable floatilla of awesome software that's discoverable right from the Apple menu of every Mac means that if you're a publisher, people are FAR more likely to try your software. I myself found a free copy of Autodesk Sketchpad in the app store that I am very much enjoying. I might end up buying the commercial product as a result - possibly through the app store! (See caveats below for why I might choose the shrink wrapped version.)
Ease of installation - just like on the iPhone and iPad, you click "Buy" or "Install" and *BOOM* it's on your machine, happily bouncing in your dock. For non technical people, this is a godsend. They do not want to know about .dmg files, dragging apps to the Applications folder, or the like. Yes, I know, this is VASTLY easier than the folks in the Windows world have it with their highly complex installers, but even still.
One Stop Shopping for updates - Sure, lots of devs these days are bundling some kind of update mechanism into their apps, but this is once again - seamless and easy to use for non technical people.
Of course, every silver lining has a cloud attached, so there are a few down sides:
Inflexible upgrade path - Apple has imposed rules around publishers app store offerings, I don't know all the details, but I do know that publishers are not happy. They want total control of how they monetize the sale of upgrades for their customers, and to a certain extent I can't blame them. Over all I think the net winner here is the consumer, so we'll see how many publishers sign up and grudgingly cope with the new rules.
Restrictive rules about permitted content - Nothing sexy, nothing violent, no Java or Rosetta, just like the IOS app store.
From my perspective, people who object to the app store on OSX are on shaky ground, because unlike the IOS world where the app store is the ONLY way to get apps, the app store on OSX isn't. You can still install apps the old fashioned way, and Apple has given no indocation that they intend to do this now or at any time in the future. I don't think it's in their best interest to do this, and I think people who are predicting imminent doom really need to get their collective head checked.
Then again, geeks do have a propensity for hysterics.
To sum up, I think everyone (publishers, consumers, and the wider Mac community) has everything to gain and nothing to lose from the app store, and I for one welcome the addition.