God some people are paranoid.
The App Store (and companion changes in the OS such as full screen apps and hands-off installing) is, possibly, the biggest jump forward for an OS for the last five years and I'm totally serious about that. What Apple have done is taken the same OS X we have today and, with that simple addition, made it infinitely more user-friendly for non-techies.
At the same time they're giving developers another route to market that, yes, takes 30% of their income but offers a huge potential upside. For a start it removes any worries about hosting, allows you to process credit card transactions and handles updates for you - all major problems when you're going it alone. But the big benefit is, surely, obvious - the potential audience for your app is vastly improved over whatever interest you can drum up hosting an application and marketing it yourself. If Apple take 30% but you sell twice as many copies of an application then you're up on the deal and that's assuming that you manage to get your hosting, payment processing etc for free.
As for 'FEAR the app store'.... why would you? Apple are NOT stupid, they know there's a core group of users who demand the freedom to install what they want on the desktop and that functionality isn't going away anytime soon, if at all. They haven't removed one single feature from OS X (as far as we know at this time anyway) that makes it any less of a 'pro' OS. As an aged geek and occasional developer the idea is fascinating and, by far, the most exciting development in computing for years. Digital distribution is the way of the future and Apple just delivered it with a proven model at a fair price for devs and, more importantly, to a very large install base. The potential is massive and I'll guarantee there's a lot of independent developers looking at this VERY seriously at the moment.
Frankly this sentiment seems to be coming from a vocal minority of geeks who see the move of computers into mainstream society as some sort of threat to be fought. This is just nuts, the computer is increasingly becoming part of our daily lives in the same way pen and paper was. As developers, sys admins, tech support - whatever your involvement in this industry may happen to be - we have GOT to start realising that the next big step is going to be taking what is still, at heart, a business device designed for a certain level of knowledge and turning it into a true consumer platform. Apple today took a massive step towards that and I will guarantee that Microsoft are going to be looking at that Summer 2011 delivery date for Lion and worrying. If we don't see an app store in Windows 8 I'll be astonished.