I think if Walker continues to holdout, Driver's ADP will slide closer and closer to his true value. I wouldn't want to spend more than a 5th round pick on Driver... I have Driver as a relatively safe WR to reach the top20 WR status, but I don't know that he has the upside of other WRs that are selected in the 4th round like Darrell Jackson or Nate Burleson.
I have him currently slotted to go for: 75/1100/9
IMO, if Walker sits out the year, the real boost in value goes to WR Robert Fergueson (he would start in Walker's place) and to a lesser extent RB Ahman Green and TE Bubba Franks (greater emphasis on secondary passing options).
Walker brings a lot of things to the table.. and it's really hard to judge how his absence will affect Driver. At first I thought great, now Driver gets all the targets... but in order to do that you really have to downplay the impact that Walker brings to the game. He is one of the few WRs in the NFL that is strong in every aspect of his game. Single cover him short and he overpowers you to make the first down. Single cover him down the field and he outleaps you and goes for 6. IF CBs try to tackle him one on one, he's got a good chance of breaking loose.
People don't seem to realize how much affect Walker has on the deep coverage that opposing secondaries run against GB. Similar to Moss and Chad Johnson, you can't single cover Walker down the field and expect to get away with it. Therefore you can't really double cover Driver in '04. Without the dynamic that Walker brings, Driver will see a lot more targets, but he will have to fight through a lot more coverage to get open and make easy catches.
I think Driver can overcome the added coverage and convert some extra targets on his own skill set, But it could really hurt his big-play and YAC ability if he is constantly swarmed by bodies in the secondary. For a WR that routinely averages 14-15 ypc when healthy, Driver could take a signficant hit in that regard.. How much would the extra targets help to offset the big plays? It's hard to say.
I would modify his numbers to look more like 85/1100/8 without Walker.