Scrambling to find a launch date for the Samsung Galaxy S 4? Staples may have just dropped a hint. According to a leaked store training sheet, AT&T will be offering the next Galaxy phone on April 26th, followed by T-Mobile on May 1st and Verizon on the 30th. Bold lettering warns these dates are tentative but they are familiar, matching both the UK launch date and T-Mobile's own declarations. Naturally, we try to take these things with a grain of salt, though it's worth noting that the document asks stores to prepare GS 4 reservation signage on 4/15, one day before official pre-orders begin. It isn't an iron-clad case for the phone's launch by any means, but for the eager Galaxy fan, tentative is better than nothing. Skip on past the break for a peek at the full page.