Given the incredibly crunched timeline involved with the end of the NBA lockout and the start of the regular season, quick decisions will be everywhere for Geoff Petrie and the Sacramento Kings. But a rule change in the new collective bargaining agreement will specifically affect the future of Marcus Thornton, should the guard wish to test the free agent market.
Thornton is a restricted free agent, meaning that he can sign with any team he wishes for whatever amount (within cap rules) they offer. But his RFA status means that the Kings can match any offer sheet he signs. That puts Thornton under contract under those terms with Sacramento.
In the old CBA, the Kings would have seven days to make a decision. All the while, the cap space allotted for Thornton for the signing team would be tied up. This "cap space hostage crisis" feature tended to make restricted free agency a real burden for players; few players in restricted free agent signed truly outrageous offer sheets. (Paul Millsap and Wes Matthews signed big contracts, but nothing like some of the second deals players sign with their own teams.)
The shorter matching window should open up offer sheets a bit, and if Thornton tests the market, a team could toss a fat offer quickly, forcing the Kings to decide whether to match.
More likely, however: Thornton and the Kings will reach a deal quickly, allowing Petrie to take a look at the market at other positions, including the frontcourt. The shorter window will likely mean more to Sacramento a year from now, when J.J. Hickson, Jason Thompson and Donte Greene are scheduled to become restricted free agents.
One more place where it could matter: the Kings can throw some of their famous cap space on other teams' restricted free agents without fearing that they'll lose too much time in the period. That means players like Marc Gasol, Thaddeus Young, Jeff Green, Rodney Stuckey and (um) Greg Oden could be in play more than they would have been under old rules.