If taking public companies private is the hot new thing in megabusiness, the Dolans just became the most fashionable billionaires out there: After three years and three failed attempts to privatize Cablevision, Chuck and Jim have just worked out a deal with their company’s board that will restore the family’s total control over their lumbering brainchild. Cablevision, which comes complete with holdings like the Knicks and the Rangers, Radio City Music Hall, and over $12 billion in debt, will change hands for $10.5 billion in cash. With the liabilities worked in, that adds up to almost $23 billion. The Dolans pledge to cash out the current shareholders at $36.26 a share, which is their highest offer yet — a hearty 11 percent over the stock’s actual value as of yesterday. We learn all this from the Times, of course, where the Sulzbergers are no doubt paying attention. One hopes.