Nintendo has confirmed their next Nintendo Direct presentation will take place tomorrow, August 29.
The focus on the presentation will be on the Nintendo 3DS and Nintendo Wii — not to be confused with the Wii U which is currently in the middle of a release date rumor war. For Wii U news, I suggest waiting until Nintendo's press event in September where Nintendo of America President Reggie Fils-Aim will address "how the Wii U will change the future of gaming and entertainment".
As for tomorrows Nintendo Direct, it'll be Wii and 3DS. The presentation will go live tomorrow, Wednesday, August 29, at 8:00pm JST. That's 4:00am PST for us in America and 12:00pm BST for the UK.