Well, iOS 4 was indeed released, but many users are reporting being stuck at the backup stage on their device. So, if you have not started the install of iOS 4 yet, tekgoblin suggests holding off and seeing if Apple has anything to say about this. It seems that the backup that the update performs before the update is crawling incredibly slow for some reason.
there are lot of issues coming in IOS4.
Its just strange that the backup is taking forever, when a standard backup is quick.