J. K. Rowling's Draco entry on Pottermore, added December 2014, directly addressed your question.
The biggest revelation was that he became less of a pure-blood fanatic:
The events of Draco’s late teens forever changed his life. He had had the beliefs with which he had grown up challenged in the most frightening way: he had experienced terror and despair, seen his parents suffer for their allegiance, and had witnessed the crumbling of all that his family had believed in. People whom Draco had been raised, or else had learned, to hate, such as Dumbledore, had offered him help and kindness, and Harry Potter had given him his life. After the events of the second wizarding war, Lucius found his son as affectionate as ever, but refusing to follow the same old pure-blood line.
Draco married the younger sister of a fellow Slytherin. Astoria Greengrass, who had gone through a similar (though less violent and frightening) conversion from pure-blood ideals to a more tolerant life view, was felt by Narcissa and Lucius to be something of a disappointment as a daughter-in-law. They had had high hopes of a girl whose family featured on the ‘Sacred Twenty-Eight’, but as Astoria refused to raise their grandson Scorpius in the belief that Muggles were scum, family gatherings were often fraught with tension.
Also, he seemingly mellowed out a bit, leading a life of leisure instead of working to overturn the forces of light or establisg dominion over Muggles, like Lucius did:
I imagine that Draco grew up to lead a modified version of his father’s existence; independently wealthy, without any need to work, Draco inhabits Malfoy Manor with his wife and son. I see in his hobbies further confirmation of his dual nature. The collection of Dark artefacts harks back to family history, even though he keeps them in glass cases and does not use them. However, his strange interest in alchemical manuscripts, from which he never attempts to make a Philosopher’s Stone, hints at a wish for something other than wealth, perhaps even the wish to be a better man. I have high hopes that he will raise Scorpius to be a much kinder and more tolerant Malfoy than he was in his own youth.