Bob Jones has dropped his defamation case against Renae Maihi. Good. But at the same time, it perfectly exposes what the case was all about: not protecting Jones' reputation, but punishing someone who had dared to criticise him, and deterring others from doing the same. This rich pompous asshat dragged a young women into court and heaped costs on her just because he could. And he walked away when he got bored (and when she was about to be able to have her say) because he could afford to do so. Its a disgusting abuse of power, and it shows exactly what is wrong with defamation law.
As for what to do about it: the US, Canada, and the ACT all have laws against "SLAPPs", and adopting one would be a good start. But the problem is that fines and damages mean nothing to the rich. Jones was willing to wear the cost of a pointless defamation suit just to discourage and intimidate, and doubling or trebling those costs is not going to make someone like him stop. Fundamentally, we need to change the law, and do away with defamation law as we know it. Graeme Edgeler has some good suggestions on this, such as limiting cases to malicious falsehoods which cause financial loss (rather than simple name-calling and expressions of opinion). Moving cases out of the courts and into a more accessible tribunal would also help a lot, and remove their use as a legal weapon of the rich against the poor. But fundamentally, in a free and democratic society, it should not cost you a year of your life and hundreds of thousands of dollars if, you express a reasonably held opinion that someone is of poor character. Being judged by others for your actions is part of life, and rich pricks like Jones need to accept that.