The front office could re-sign him, but if he signs elsewhere the Nets will be looking for his replacement. The best place to do that is in the draft. The talent is young and impressive. A possible replacement is just waiting to be found.
In the 2012 NBA Draft, the Nets can get a top-three pick and another pick at No. 16. If this happens then Williams might stay. But if the Nets fail to nab a first-round pick by not getting a top-three pick in the lottery and/or the Houston Rockets fail to make the playoffs, then Williams is probably gone, and he leaves a big hole.
Here are five guys that could fill said hole.