Stay sharp, Time Warner Cable subscribers -- we've got a feeling the switched digital video wave is just beginning to swell. Merely hours after hearing that San Diego residents were receiving a letter informing them that SDV was on the way, one particular user in Kansas City has apparently received the same. Better still, he was kind enough to post the full text, which explains that a number of "lesser-viewed" channels will be delivered via SDV as of August 20th. Of course, this means that existing CableCARD users will be out of luck unless they pick up a tuning adapter, and while some carriers have already committed to handing them out to those in need for free, TWC is entirely more ambiguous. The exact verbiage reads: "It is currently contemplated that the Tuning Adapter will be provided at no additional charge," but those unwilling to wait will be forced to pick up one of the carrier's own set-top-boxes in order to see the stations. [Disclosure: Engadget is part of the Time Warner family]