For the NBA this partnership could have mixed outcomes. While it hits a significant part of their fan base, it is also a controversial law that could alienate the part of it's fan base who happen to be the drivers of the financial spend for tickets, concessions, and merchandise. For now.
More importantly it will impact their players. According to data listed on ESPN.com there are 534 players who received compensation during the 2012-2013 season. Of these, 492 earned more than $250,000. This is the magic number for paying the additional Medicare tax of 0.9% when filing as joint married. (I know some players are single but just bear with me)
Total salaries for all players over the threshold come to $2,021,287,266 which means that NBA players will be paying $17,086,835 in new Medicare taxes this year just on their salaries.