Well it is assured that the Iphone 4th generation will be released by June 24th with the price of 199$ or 299$ and a 2-year contract with AT&T.
There are many rumors about that.
But as far as my opinion is concerned,
the new second generation iphone will come out in beginning of year 2011.
The second generation iphone is believed to have multitasking feature as well.
For more information you can visit apple`s home page http://www.apple.com/iphone.
I hope you will get all necessary information and latest news from there.