This morning, in a press event, Steve Jobs, Apple CEO and his executive teams gave a preview of the upcoming iPhone OS 4.0.

The operating system that powers the iPhone, the iPod Touch and  new iPad. The SDK is released today to third party developers and Apple is expected to ship this summer.

This is a major release of the iPhone OS platform. focusing on seven majors areas  that Jobs calls “Tentpole”

Tentpole-1: Multitasking

The existing iPhone OS only allows 1 task running at a time, except some built-in apps such  iPod, Phone, SMS,… The multitasking is the most asked feature. Apple will implement it with the iPhone OS 4.0 via several API’s  (application Programming Interface). Pushing on the home button will pop up a small dock located at the bottom of the screen. The dock shows the background tasks.

1. Background audio API:  App that play audio such Pandora now can run and play music in the background. Similar to today iPod app
2. Background VoIP API: Phone alternative apps such Skype can run in the background to keep the user status online, any incoming activities will invoke a small notification pop-up window to allow user to reactivate the app for further interaction.
3. Background Location API: App using GPS such navigation guidance TomTom running in the background still can give driving directions. Other social location based apps running in background can only get cell tower triangulation instead of the GPS.
4. Push notification: Apple did not elaborate on this feature, which has been available for sometime in the current release
5. Local notification: Now third party can initiate push notification without going through Apple servers
6. Task completion: There are some apps that take awhile to complete a task. Like uploading pictures to flickr — now it can continue to upload pictures in the background
7. Fast app switching: It’s what allows applications such games to save its state and stop running, and then restart instantly where you left it.

Tentpole-2 Homescreen

1. Folder: With its popularly, apps are filling up the homescreens. Apple will give the ability to group app icons in folder. Just drag one app on top of another and it instantly makes a folder. It also automatically names the folder based on the categories of these apps
2. Homescreen Wallpaper can now be set with any image

Tentpole-3 Enhanced Mail

1. Unified inbox: all mail in one inbox
2. Fast inbox switching to focus to the main account
3. Organized by thread a la Gmail
4. Open attachment: The ability to get an attachment and open it with an app for the app store.

Tentpole-4 iBook

Similar to iPad, users can purchase iBook once from iTunes and can be read anywhere, sync page and bookmark wirelessly across platforms

Tentpole-5 Enterprise

1. Data protection, mobile device management, wireless app distribution…
2. Multiple Exchange account support, Exchange 2010 support and new SSL VPN options

Tentpole-6: Game Center

iPhone, iPod Touch and iPad are getting traction with gamers. Apple will add social gaming network features such: invite friends, matchmaking, leaderboards, achievements,…

Tentpole-7 iAd: Mobile Advertising

Apple is getting to the advertisement segment with Apple’s January acquisition of a mobile ad network called Quattro. Each iPhone OS user spends in average 30 minutes per day on app, if Apple embed 1 ad every 3 minutes. This equates to about 1 billion ads delivered per day.

Apple promises to deliver better quality ads  with interaction and emotion while letting user stay on the app. Apple to sell and host the ads and share 60% to developers.