Anything still floating after that impact would be indistinguishable from all the other floating garbage.
I disagree. There would be a great debris field from any crash into the Indian Ocean. All of the crashes that I have heard about have had pieces from the plane and bodies floating on the surface. Air France Flight 447 is a case in point. There is a lot of things on a 777 that will float.
The reconnaissance satellites we have looking down at the Earth should have seen Flight 370 as it flew on its diverted course. These things do see things like license plate numbers. A big 777 should be no problem. It is very strange that not one word has been said about what these satellites did or did not see. That tells me they did see something and they don’t want to reveal what they saw. Perhaps a “combat landing” in Iran is something they want to keep quiet.