Honestly, it sounded more to me like Sony Pictures wanted this film made. They know it's marketable, they know that they'll see those dollar signs. Unfortunately though they weren't quite willing to negotiate the huge sums of money for the contracts, which a) is not logical considering the sum they paid Smith, Jones, and Sonnenfeld for MIB 2 and b) despite what you're hearing about Sony's financial problems they still have billions that they have to spend much like a record label. If things go awry they could just write it off at the end of the year.
I think this all rests on the legal hands of Mr. Murray, who just didn't want to release or sell his rights to the film, period. As much of a bad guy as it makes him seem, I'm sure that he has his reasons. Probably the same reasons that he wasn't willing to do the second Charlies Angel's flick (even though in my own opinion, he was the only thing that film had going for it).