"What they will want to see is a frog becoming a giraffe before they are convinced....."
This is a really good point, and one that gets pushed aside quite frequently when debating occurs between the evolutionary scientists and creationists. It seems as though creationists are in some way convinced that macro-evolution is the type of evolution that's being touted by science as "fact". In reality, they're just making a claim that tries to discredit evolution by way of science being unable to prove that macro-evolution has ever taken place. This is a logical fallacy at its core.
Evolutionary science, to my knowledge, has never operated on the premise that macro-evolution is the holy grail of evolutionary science. Evolutionary scientists, biologists, and anthropologists have always backed the theory that evolution has taken hold over millions, possibly billions of years, and has done so on a micro-evolutionary scale. Yes, that means adaptation eventually leading to the divergence of different species. The creationists are playing the wrong card, in the wrong game, while being wholly convinced that their side is "winning" the argument. That's the difference between the arrogance of faith, and the empirical evidence on which science operates. Evolution may be wholly compatible with the theory of "intelligent design". The problem, however, appears to be that those who espouse the idea of "intelligent design" seem to suffer from a complete lack of the intelligence from which they claim to have been created.