Each year we set our calendars to expect new hardware announcements around WWDC, if not actually during Apple's annual developers' conference. Last year we got a glimpse of the iPhone 4 in action. At WWDC 2009, the 3GS was announced. Naturally, many of us thought the iPhone 5 would appear at WWDC 2011, but as mentioned earlier, knowledgable sources cited by Jim Dalrymple say we shouldn't expect any hardware announcements at the keynote.
While WWDC is for developers, Apple's special magic has always included the strong integration between the OS and the hardware -- making the whole widget equals better widgets. By revealing the "next new thing" to developers, the company has traditionally pushed developers to begin considering new hardware features before the gear is generally available. This is good for consumers, who then have apps that exploit new features when the hardware becomes available.
MacRumors says that Japanese blog Macotakara reports the iPhone 5 may not ship until the end of Apple's fiscal year, which ends in September. This would still make the phone available just in time for holiday sales. This year's WWDC will be more about Lion, of course, and it seems like an iOS device announcement would simply confuse the message, "Back to the Mac."