Isn't ICS like just around 0.5%(or was it 5%) of Android handsets as of December 2011? This design guide is ALL about ICS and nothing about the 99% of the Android handsets used by people.
in 2 years everyone will have ics or better. carrier contracts.
That's kinda sad, compared to Apple, Microsoft, and RIM. ICS fixes bugs too. People shouldn't have to deal with them until they buy a new phone.