Google today explained in a blog post that it wants developers to stop creating applications that support the dedicated Menu button. Moving forward, Google wants all apps to use the ActionBar that's part of Android 4.0 Ice Cream Sandwich. Google explained, "Not only should your apps stop relying on the hardware Menu button, but you should stop thinking about your activities using a 'Menu button' at all. Your activities should provide buttons for important user actions directly in the Action Bar (or elsewhere on screen). Those that can’t fit in the action bar end up in the action overflow." Google hopes that this move will create a more uniform look and feel to the behavior of Android devices and the applications that run on them. Android devices originally shipped with four buttons, including a dedicated Menu key. The Galaxy Nexus, the first Android 4.0 device, does not have a Menu key and reflects the experience that Google is seeking.
This is by far the best example of Android's UI non-design. Although a back button isn't universally terrible (its best features are now negated by the quick-switcher in ICS and Honeycomb) , the inconsistent implementation (app state vs. system state) was always a running joke with iOS devs.
I don't know why google thinks that an All touch experience is better. I personally miss having dedicated Call/End Call buttons. Also, a dedicated camera button is functional. I have yet to see a high-end andoid with these 3 buttons. I've had the HTC chacha which was great with the buttons but had ridiculously low memory for application storage. I wish Sony would bring back the P800/P900 serious with Android and the flip keypad-- That would rule.