I personally like some buttons, and think they can be useful. For example, volume buttons so I can adjust volume of a call or music without turning on screen or looking at the phone. I much prefer button for camera zoom/focus/shot over "touch the screen to take a pic" most phones are using these days. etc.

I could use my N95 to text and write emails while phone was in my pocket, without even looking at the screen

That being said, the normal "android buttons", home, back, menu, can be made obsolete by on-screen elements or gestures (like N900 does).