Murdoch says he won't tamper with the Journal's independence, and there is every reason to believe he is sincere about that. He is, if anything, a good businessman, and the Journal is a good business. But there also is every reason to believe that his sincerity doesn't mean much.
For a description of how Murdoch's ownership of the Wall Street Journal would play out, turn to Harold Evans' "Good Times, Bad Times". Murdoch pressured Evans (better known in this country as Tina Brown's husband) out of the editor's job at the London Times not long after acquiring the paper. Murdoch couldn't fire Evans outright; he had to go through a board of directors. Contemplating his future, Evans wrote:
Nothing in my experience remotely compared to the atmosphere of intrigue, fear and spite at Murdoch's Times. ... If I fought and beat Murdoch this time, despite the odds, I would have to endure an endless assault. ... I would be subjected to a thousand humiliations, challenged on every paperclip. My energies would be absorbed not in journalism but internal politics, seeking alliances, suspecting every man's hand. I would have to keep in constant touch with the national directors and their successors, ready to justify and vindicate every editorial decision Murdoch chose to challenge or misrepresent. It would be Russian roulette. I would become frightened to pull the trigger on an empty chamber. I feared for my own character and self-respect. I had seen what had happened to others, the courtiers apprehensive on his arrival, hoping for the boyish grin, fearing the scowl, demeaning and coarsening themselves. Perhaps I would make one accommodation with Murdoch to win favour and then another, or subconsciously begin to guess what he wanted and give it to him. It was a challenge to myself I thought I could endure; but there was the contrary danger implicit in that flash of vanity. There was the certainty, it seemed, that I would become obsessed with either Murdoch or my own introspection. Neither was an attractive prospect.
Great papers aren't often killed by great calamities. They are slowly bled to death.