More than a few of you have expressed concern over the HTC One's backwards compatibility, what with it's three capacitive navigation buttons and lack of a menu button, check this out. Paul "Modaco" O'Brien has been playing around with the software headed for the HTC One X, One S and One V, and found out how HTC's UI designers have gotten around this limitation: basically, a virtual navigation area springs up on the screen when needed, doubling down on both virtual and capacitive buttons. The Menu button appears centered, and acts just like it did in Gingerbread-based HTC Sense packages.
This does seem to beg the question: if you're going to have to fall back on a Galaxy Nexus-style virtual navigation bar anyway, why bother with having the capacitive Home, Back and app switch buttons built into the hardware? Couldn't that space be used more effectively by either extending the screen or shortening the case itself, to say nothing of the small yet considerable cost savings? For that matter, if you have to add the Menu button back in for incompatible applications, why not just put the standard four buttons on the capacitive row and be done with it?
HTC isn't alone in its insistence on keeping hardware buttons alive with Ice Cream Sandwich. Pretty much every single new phone that we spotted at Mobile World Congress combines a high-definition screen, Android 4.0 and the familiar lower button row. Manufacturers will need to address this interface quirk themselves, or face some immediate customer backlash when they find that the higher functions of older apps can't be accessed on a new phone.