Well, well. Android Central got a hold of a leaked document revealing that T-Mobile's 4G Mobile Hotspot, the first of its kind for the carrier, is slated to go on sale April 13th. We're inclined to believe it, since T-Mo just confirmed that the LG G2X, also named in the doc, will indeed go on sale April 15th. Alas, if you've been waiting for more info about the pricey, Honeycomb-powered