On July 13th, Japanese gamers that prefer a white Wii U over black, but don’t want the Basic Set, will be able get either color in a Premium Set, for approximately $300. That same day, Nintendo will also be releasing a new fast-charging Wii Remote pack ($25 stand alone or $40 with a Wii Remote).
And on July 25th, for around $30, Nintendo will be selling a replacement battery for the Wii U GamePad, that extends the playtime from its current 3-5 hour charge to a 5-8 hour one. If other markets get similar upgrades, PGN will let you know.