I found the final episode incomprehensible, without the on-line explanation (that someone else linked to here).
After looking at that explanation, one sees that the show producers think that all lawyers, at least defense attorneys, inevitably become evil. Including Diane and Alicia. There have always been obvious parallels meant to be drawn between Alicia and her husband, and the Clintons. I think the lack of truthfulness of Alicia and hubby are meant to convey the show producers' political message, that you shouldn't support Hilary Clinton - don't forget that it was implied in other episodes that the Democratic party won elections through ballot manipulation, with and without electronic ballot machines. (Incidentally, Electronic voting machines were created by a company run by a Republican political operator - see http://commondreams.org/headlines03/0828-08.htm
- who contributed a lot of time and money to the Republican cause, one of the main reasons the Democratic party fought them. Though yes, like any Windows machines, presumably all political actors, including Democrats, can manipulate them, and The Last Hack Wins. There probably hasn't been an honest election since the advent of electronic voting machines, if there ever was. Hanging chads were better than easily hacked Windows boxes.)
Diane was already quite evil - using unethical strategies to get rid of her male partners, and plenty of unethical legal strategies. But she was completely justified in slapping Alicia, who impugned Diane's husband, one of the few relatively honest people on the show, in open court, unfairly.
I've enjoyed the show a lot. But I think a show should stand on its own merits, and the final episode should not require separate on-line explanations. That was made worse because the link to that explanation at cbs.com was initially hard to view - I couldn't make it display under Firefox (finally used Chrome), or on a Google TV mobile device.
I didn't like the ending episode. It feels like they want us to hate all the main characters, not a good thing for any show. It also felt like it needs sequels to complete the story.