Filed under: WirelessIt's April, do you know where your WiMax service is? Unfortunately, S.Korea as Sprint backtracks on the planned April launch of its commercial Xohm service. This according to an official company spokesman. Sprint says that the launch has been delayed to "later in the year" which many expect to be as early as summer. Even then we're likely only talking about Chicago, Baltimore, and D.C. areas. Time to start making room for LTE in our sad, jade