Martin always intended Daenerys to become the Mother Of Dragons who would lead an invading army into Westeros with her dragons in tow, but her journey to that point would have taken some different turns. For a start, her brother Viserys wouldn't have been such a prick, and she would have loved him dearly, leading to her vengefully murder Khal Drogo for killing him. Additionally her army would have been made up of Dothraki horsemen (despite killing their leader) rather than the Unsullied, which would probably have been a little more epic - and she would have basically found the dragon eggs on her journey rather than being given them. Was It A Good Change? It's hard to even imagine Dany becoming the Khaleesi without the love of Drogo, or the lessons that her grief and her time spent with him in life would teach her. Plus, Viserys' death was an early indication of how well Martin did well-deserved death, and it's still one of the most satisfying moments. The idea of her being driven by a void - not just her birth-right, but also the loss of her husband (despite subsequent romantic entanglements) is also a very engaging image.