After all i'm sure for Lucius, Draco is probably the perfect son. He has taken his fathers stereotypes and prejudices about muggles for his own beliefs and has never shown once in the books any sympathy towards the death eaters or voldi's victims.
For example
At the age of 12 Draco 'smirks when he examines the opal necklece which had taken the lives of 19 muggles in Borgin and Burkes.
At the same stage of Draco's life his behaviour towards the victims during the attacks by the Basilisk in the chamber of secrets shows that he is confident in exhibiting these derogatory views about muggles infront of and to other students in hogwarts.
At the age of 14 in the Goblet of fire Draco again is in no doubt that the death eaters (including his father) attacking the muggles during the Quidditch world cup is completely acceptable.

I completely agree that Draco has been socialised or brain washed by his parent's to accepting the above mentioned values and beliefs relating to muggles. Because of this lack of doubt or remorse in Draco's mind I don't think Draco is about to change his views in a couple of years.

I think the only way a complete reversal will occur in Draco's opinions will only result with colossal shift in his life in two ways:

He Looses his mother either by being murdered by or while on a mission for voldi.

I believe that Narcissa is one of only three people who Malfoy really cares for, when Harry insults Narcissa in retaliation for his comments about Mrs Weasley Draco is livid.

I doubt that Draco cares as much as much for Lucius as Narcissa (as Draco appears to see Lucius, in my opinion as some one who can provide him with physical things and power, a place on the slytherin team, a nimbus 2001 etc). I do however believe hat if Lucius was killed by voldi or killed for voldi this would make Draco question his beliefs. Lucius is someone Draco respects and probably admires greatly, as when Harry indirectly gets Lucius put in Azkaban Malfoy now at the age of 15 tries to exact revenge on Harry, on his fathers behalf on the trip Home on the Hogwarts Express.

In the Half blood prince Draco will be 16 and i think we have to ask is it to late for Draco to reject his hatred of muggles?

But the way the third person I think Draco cares about is him self and needless to say i think an attack on him self would be the third possibility of Draco forcing him self to rethink.