This isn't bad for Showtime,
Al Haymon knows that there are far more people watching commercial TV than paying for cable, dish, or U-Verse service. The potential for boxing to reach a larger audience in boxing can be achieved in this manner. Not only that, if the commercial TV audience for boxing is decent, more people may subscribe to HBO/Showtime for boxing, and even buy more PPV for super-fights. Al Haymon will put a mixture of fights on NBC,CBS Sports Network, and Spike in addition to Showtime, and HBO.
Boxing is about getting general public interest exposure with good quality fights. Hopefully this system won't just be a "special treat" kind of thing like TNT did years ago and never touched boxing again, or in 1995 when two competitive dates with PPV's Bowe-Holyfield III and Tyson-Mathis fell apart and Tyson-Mathis landed on FOX, but Fox I don't recall FOX doing more boxing.
Haymon has so many fighters in his stable, he's not dumping Showtime, just using more commercial broadcast networks to begin to get the general public interested in boxing that goes beyond the wishful thinking of Mayweather-Pacquiao.