The Apple OS 4 Event is over, so what will we get in OS 4.0 this summer? Well first of all there’s over 100 new user features, so that’s quite a lot. But the 8 most important are Multitasking, Custom Backgrounds, Folders, Unified Inbox, iBooks, Game Center and iAd Advertising. We will tell you all about these new features after the break.

Multitasking: Steve Jobs said “Now we weren’t the first to this party, but we’re gonna be the best. Just like cut and paste.” “It’s easy to do this in a way that drains battery life, and a way that reduces performance of the foreground app. If you don’t do it right, your phone will feel sluggish.” He said it took so long because they need to figure out how to implement multitasking for third party apps and avoid those things. He showed a demo today that’s looks pretty cool, when you double tap the home button a window raises that shows all the apps that are running.

Custom Backgrounds: A simple but nice extra is the ability to set a custom background to your springboard. Now you don’t have to jailbreak your device anymore to do this.

Folders: Another thing jailbroken iDevice users can do is sort all of your apps into folders just like you do on your computer, now we get it in OS 4.0. Another jailbreak reason gone. Thanks to Folders it is possible to put up to 2160 Apps on your iDevice instead of 180.

Unified Inbox: The Mail App has been updated so we can see all our mail in one inbox and we can use more than one Exchange account. Another new function in the mail app is the ability to get an attachment and open it with an app for the app store.

iBooks: Not much to talk about here, all I can say is that the iBooks ebook reader will come to the iPhone. I don’t know if a lot of iPhone users will use this, because reading on a little iPhone screen isn’t that good as the 10 inch iPad screen.

Game Center: They want to make gaming even better on the iPhone — so they added a social gaming network. Its just like  Xbox Live, or something a lot of iPhone users know “OpenFeint”. But this will be bigger than ever, you simple go to the game center, choose the game you would like to play and you will automatically be connected to someone to play with. Looks promising.

iAd Advertising: So Steve explain to us what this is. “We have a lot of free or reasonably priced apps… we like that, but our devs have to find ways to make money. So our devs are putting ads into apps, and for lack of a better way to say it, we think most of this kind of advertising sucks.” Steve said. So because of that they created their own ad application which will probably be a success because “The average user spends over 30 minutes every day using apps on their phone. If we said we wanted to put an ad up every 3 minutes, that’s 10 ads per device per day. That would be 1b ad opportunities per day.” Normally when you click on an ad “it yanks you out of your app and throws you onto the advertisers web page” with iAd you will never leave the app when you click on an ad. The ads will also look better (almost like little apps).

A dev preview has been released today. There is just one downside, OS 4.0 will not be the same for all iDevice users. For example Multitasking will only be available on the iPhone 3Gs and iTouch 3G. Also the iPad won’t get the 4.0 upgrade until Fall.

Photos [engadget]