What exactly is it that they would be working on? HD seems to be a finished product and I am not even sure where improvements could be made other than cosmetic changes that would satisfy some while displeasing others.
For a long time, users were asking two major improvements to the game: (1) reduce the number of timeouts being called during end-of-game play and (2) only utilize conference games for determining conference awards. WIS heard those demands from users and with no small amount of blood, sweat, and tears made those improvements to HD.
Other than the occasional coach who gets upset that his/her team with a higher overall rating lost a game, I can't think of a single complaint users have about this game. So again, what exactly is it that they would be working on?