As long as HTC continue to fail at branding and marketing, along with the other Android phone manufactures, I don't think Samsung really has to worry about changing anything. What they are doing is working very well for them. Why screw around with success.
I wish Samsung would consider using something other than plastic. I am not saying this affects build quality, I had a Vibrant and Galaxy Nexus and they were very nice phones. For me it's not the build quality, but the feel of the phone. The plastic just doesn't have the premium feel as other phones. But on the other hand the phones are lighter and more comfortable in the hand.