Apple's iPhone OS 4

Apple is unveiling its new OS 4 today and it looks pretty nice!

Rumors about Multitasking is true for one. and it looks pretty neat.

So what is included in Multitasking:
Background Audio
Voice Over IP
Background Location
Push Notifications
Local Notifications
Task Completion
Fast App Switching

Folders which is like CategoriesSB hmmm Apple is catching up!
Drag and Drop UI
Intelligent Naming
From 180Apps on the iPhone to 2160 Apps

Now you can change the Wallpaper aka Winterboard

Unified Inbox, all your email in one inbox, multiple exchange account are allowed now.
Open up attachments with Apps from Appstore
Fast inbox switching
Threaded message

iBook on the iPhone
with free Winnie the Pooh.. hmmm
Buy once, read anywhere

Enterprise

seems really boring...

Game Center

Social Gaming Network
Invite Friends
Leadership Board
Achievements
Matchmaking

iAd

Emotion + Interative
Ads keeps you in your App
Build onto iPhone OS - hmm now that sucks.
Apple Sells and Host the Ads
60% -> Dev hmmm is Apple taking a large pie here?
I believe Apple has nailed it this time with iAd.

All this releasing to end users this summer, for iPhone 3Gs and iPod Touch 3G, also to iPhone 3G and iPod Touch 2G but sorry no multitasking for them, no mentioned about iPod Touch 1G thou...
For iPad it is releasing this Fall.

Photos taken from Live feed of Engadget