PC World: "A small change regarding the look and feel of Ice Cream Sandwich apps could help Google fight Android fragmentation.
The Holo themeStarting with Android 4.0, support for the "Holo" theme will be mandatory for phones and tablets that have the Android Market installed. Holo is the stock Android theme, known for its sharp angles, thin lines and blue hue. Third-party developers can now create apps and widgets using the default Android aesthetic, knowing that's how it'll look on every major Ice Cream Sandwich device that has the Android Market.
To be clear, this doesn't mean the death of phone makers' user interface customizations, such as HTC's Sense or Samsung's TouchWiz."