iOS 6 beta release , which is expected to happen tomorrow at the World Wide Developers Conference in San Francisco is rumored that will not have support for older devices.
It's not unusual for Apple to drop iOS support for hardware a couple of generations old, and that is the rumored fate of the original iPad or third-generation iPod Touch.
The supported devices for update appear to be the iPhone 4, iPhone 4S, and iPhone 3GS, as well as the fourth-generation iPod and both versions of Apple TV.
Rumors suggest we might see certain developments in the MacBook series. Another expected debutee would be the final version of Mac OS Mountain Lion
Apple is famously secret for not offering much advance notice about upcoming product or technology announcements. But the iOS6 banner that workmen installed inside the Moscone Center, the San Francisco venue for Apple's Worldwide Developers Conference that starts tomorrow after the official announcements - June 11 at 10 am (1am GMT+8)
Source: CNET.com And GSMarena.com