The Washington Business Journal reported this morning Monday that Carpool on Fairfax Drive will be torn down in favor of building something the Arlington area clearly needs more of — condos. D.C.-based Donohoe is behind the plans to replace the billiards hall with a 232,500-square-foot mixed-use development of condominiums and retail outlets. Over at Pygmalion in a Blanket, the Nabob sums up our feelings about the news far better than we could: Where does one…