I've often read is that the absence of free agency might change the way teams approach the draft. Jon Dove wrote that "we could see team need trump team value" during the draft.
I'm thinking it will just shuffle the timing. Instead of seeing what can be done to improve your team in free agency first, the draft comes first. If the draft doesn't provide a certain player, then it will have to be addressed in free agency (or via trade). It's still the same two avenues used every offseason.
The Packers rarely use free agency, and rely heavily on the draft, they do make decisions every year about their own free agents. I suspect the Packers have already decided on the futures of WR James Jones, RB Brandon Jackson, and DE Cullen Jenkins. If the draft comes first, and it doesn't work out like they hoped, maybe those players chances of returning increase.
Maybe it even helps the Packers make decision about free agency. I don't expect they would have re-signed RT Mark Tauscher last year if they knew they would draft RT Bryan Bulaga, who was projected to be drafted earlier than he was.