According to Kassim Osgood's Twitter:

Jamal Williams is officially gone too! who is next? stay tuned. and thank u guys for the support. damn good people following me. (tears)

I think I know Kassim well enough to know that he's not one to play games like that, especially with a team leader like Jamal.  If the big NT really is being released by the Chargers, I get the feeling it's going to be more of a retirement.  The man has had so many injury issues in past seasons, it makes sense that he would be done with the rehab and would want to get out while he can still walk.

This may have played a part in the Chargers tendering Darren Sproles with the 1st and 3rd, because without Jamal the Chargers will unquestionably have to use their 1st round draft pick on a Nose Tackle to replace him.  That means you can expect a lower pick to be used on a RB that can share the load with Sproles and Mike Tolbert.