From Vinnie Ager at Sporting News.com:
Asomugha won't be returning to the Raiders. In addition to Houston and Detroit, his other rumored destinations include Philadelphia and Green Bay. For a player who just turned 30 last Wednesday and has never made the playoffs in eight great seasons, the latter two teams are surefire paths to the postseason.
While I recently wrote that Nnamdi Asomugha can help any team, which does include the Packers, it would come at a cost. Sam Shields would lose playing time, but not completely, because the Packers do line up with four cornerbacks at times. No more Jarrett Bush sightings! And in addition to trading LB Nick Barnett ASAP, and releasing RT Mark Tauscher, they'd probably have to release a couple other highly paid players to afford a possible annual salary of up to $20 million for Asomugha.
Instead of debating the merits of it, maybe it's better just to realize that it's highly unlikely they'll attempt to sign Asomugha. GM Ted Thompson has historically taken his time with roster decisions, and he'd have to move fast to sign him and make room under the salary cap.