Good. Now I have your attention. We learnt yesterday what the iPhone Software Development Kit is all about and what developers will be able to do with it.

The ever reliable Fake Steve Jobs called it a little unsubtly with a long list of companies that he now deems ‘dead’, perhaps over-egging the consequences, but even at this beta stage, the iPhone SDK hints of a truly practicable move away from the desktop. The whole video from the launch is available here. Here’s why it marks the Death of the Desktop – in no particular order:

OS X

Apple, predictably, has leveraged and built upon the operating system seen in its desktops and laptops. This means developers can produce desktop quality applications but specialise them for mobile usage. The free SDK builds upon Apple’s Xcode developer tools, but with an additional simulator and remote debugger and an Interface Builder for quick realisation of an iPhone friendly user interface. The result will be rapid migration of existing desktop-bound Mac OS X applications to the iPhone.

The Thick-Thin Client

I’m a great fan of web applications and I had no problem with Apple declaring Web 2.0 as the choice application development solution when the iPhone was launched last June. However, with limitations on network speed (when outside of wireless internet connectivity) and Javascript performance, together with Web 2.0 applications becoming more client-centric (moving more business logic over to the client rather than the server), some web applications are clunky with the iPhone.

The SDK provides an alternative solution: Develop an iPhone client application that provides the presentation logic but keep the business logic on a server on the internet. That’s ideal for applications that require co-operation amongst a number of users.

But the way software development is going, particularly on the web, is agile, which means releasing updates often. What happens when the presentation logic needs to change? This is where the Apple App Store comes in.

The App Store

Living alongside the iTunes Store, the iPhone will include an application store, allowing owners to browse, buy and download applications on their iPhone, either through EDGE or Wi-Fi connections. Moreover, the App Store will notify users when their application has been updated and allow them to download the update. Apple handle the storage, billing and downloading of the application, in exchange for 30% of revenue. Free applications won’t cost anything to their developer. Some people are complaining about this 30%. Tough – it’s nothing.

Casual gaming

Casual gaming is a huge growing sector of personal entertainment. If you’ve watched the video you’ll see what can be achieved on the current iPhone technology: ‘minor’ things like a three-dimensional accelerometer, three-dimensional audio, Core Animation etc. Now think what will happen when the internet comes in: social casual gaming. The social and casual nature of gaming will draw more players away from their desktop.

The Mac-only SDK

Oh yeah, perhaps one use of a desktop or laptop will remain – developing iPhone applications. That means more people buying Apple kit and less people developing for other platforms, because once you’ve developed for OS X, you probably won’t want to develop for any other operating system.

The $99 obstacle

If the 30% revenue cut is one obstacle to developers, the $99 fee to test on an actual iPhone is another. That’s cool, because it stops the store being swamped with stupid simple applications. Hopefully, we won’t get 100 RSS readers when the App Store launches, which brings me onto:

The June launch

I know people are complaining the App Store (along with the rest of the iPhone 2.0 software) won’t come until June. That’s a smart move, because it gives developers three months to get their applications developed and tested. We should get quality applications immediately when iPhone 2.0 arrives.

The iFund

That’s $100,000,000 to support new business ventures centred around the iPhone. If you’re a start-up, that’s money offered to iPhone development rather than desktop development or other mobile devices.