Amazon has put up a listing for the Hori Nintendo Switch Joy-Con Charge Stand, revealing some additional details and images. If you are interested, the charging stand, which has been officially licensed by Nintendo, is available for preorder with this link from the shopping website. You can also check out an image of what the Joy-Con Charge Stand packaging looks like just below this paragraph (more photos can be viewed from the listing).
The Officially Licensed Hori Nintendo Switch Joy-Con Charge Stand can charge up to four controllers at once. It features secure rails to keep the Joy-Cons in place as well as LED indicators to display the charging status (it will turn from red to green when fully charged). You can check out the full product description of the Hori charging station below (via the aforementioned Amazon listing):
Officially Licensed by Nintendo. Charge up to 4 Joy-Con at once with the convenient Nintendo Switch Joy-Con Charge Stand by HORI. Simply plug into the Nintendo Switch Dock and slide Joy-Con onto secure rails. LED indicators turn from red to green when fully charged. (Joy-Con sold separately.)
The Officially Licensed Hori Nintendo Switch Joy-Con Charge Stand will be released on the 18th of April in the North American region.