I would think that the speed and quickness of the player would be incorporated into the handling, driving, outside defense aspects of the player.
In addition, I don't know if it has been brought up, and I hate to use HT examples, but has there been any discussion into creating "specialties", such as quickness, vertical jump, unpredictability (like Ron Artest maybe-severe mood changes and impact on form), etc.?
That would allow the basic attributes to remain, but allow for the introduction at a later date of specialties.....
Just a thought...and see, I didn't say anything negative!!