There is only one difference between micro and macroevolution.... time. The processes which create variation remain relatively unchanged.

Although the whole WoW to evolution comparison is horribly flawed, you must understand that it might not be best compared to a "dwarf turning into a troll." The best analogy I can muster is that it would be more like a troll and a dwarf having a common ancestor a great deal of time ago.

We simply have not been around long enough to even observe macroevolution (although there is some interesting observations regarding microevolution), and it would not be some magic "ah ha!" moment where we would see a dwarf giving birth to a baby troll. The variations are slight, and as certain groups of a given species in various areas find a new niche, or deal with any change in environment, those whose genes allow them to more easily survive and pass on those genes. Given enough time, those variations would continue until there would be distinct differences (such as say a wolf and a domesticated dog). As even more time progresses, the differences in genes would be so much that they could no longer mate and produce viable offspring... and so on and so forth until we would consider them a "different species."

I won't even dare touch on the subject of "creationist scientists," as I'm trying to keep this civil.