After confirming with one of the owners (well, now ex-owners) that this info was approved for public dissemination, I'm sad to say that Celtic Crossings (751 N. Clark St.), in my opinion the most authentic Irish pub in Chicago, has been sold.
The original owners have been kept on as managers of sort for the time being, but the changes have already begun: there is now a big flat screen TV mounted in the back room, breaking with a 20+ year tradition (the owners believe that TVs prevent good conversation, and so refused to have one in their pub).
John (mustachioed John, that is), mentioned to my wife the desire to buy another bar somewhere in the city...so there is a silver lining, I guess. I can always hope that his new venture will also be conveniently located three blocks from my apartment