after the long wait now finally iphone os 4.0 is now available and now its names as ioS 4, The iOS 4 Gold Master Candidate with the SDK is available now to the registered developers whereas the iOS 4 update will be released to all iPhone and iPod Touch users in free on 21 June, 2010 and iPad will get that in fall 2010.
The iOS 4 includes 100 new features and 1500 APIs as some of iOS 4 features are multi-tasking, better email, Bing integration with Safari, unified inbox, apps folders, iBooks, Retina display, improved camera and photo apps etc.
The Enterprise iOS 4 version will include support for Microsoft Exchange Server 2010, SSL VPN, enhanced Mail app functionality, and data protection.
Download iOS 4 GM Candidate
Mohan Desai is from mumbai-India, student. love to write on stuffs related to Technology, Internet, computers, tricks, reviews, etc. 
Thanks Mohan for the Post.
Let me check the sdk.