There are actually two notable deadlines Thursday in the NBA. One is the buzzer sounding at midnight that signals the end of the current collective bargaining agreement and sends the league into the uncertainty of a lockout. But Thursday is also the last day for free agents-to-be such as the Denver Nuggets' Nene and the Dallas Mavericks' Tyson Chandler to sign contract extensions that would keep the two big men off the free-agent market ... whenever free agency starts after the forthcoming lockout. Read more: http://sports.espn.go.com/dallas/nba/news/story?id=6722158
