Apple closed the door this morning on any speculation that it would announce new hardware at its Worldwide Developers conference saying it would focus on iOS and Mac OS.
-The Loop, March 28, 2011
A bit too much being read into this tidbit from Jim Dalrymple about Apple's early June developer conference known as WWDC. Apple can call an iPhone event any time it wants. I doubt they want to wait until October to update the iPhone 4, which is already getting a bit long in the tooth. And a new iPhone could run iOS 4.5 or something for a few months.