To celebrate the launch of Super Smash Bros. for 3DS in Japan, Nintendo will stream 8 hours of footage from the final, English version.
For everyone lucky enough to live in Japan, Super Smash Bros. 3DS comes out this Saturday. The rest of the world will have to wait until October, but to tide you over, and to prove that the 3DS version is, in fact, 100% complete, Nintendo will be streaming 8 hours of Smash Bros. gameplay in the lead-up to its Japanese launch.
Nintendo of America just announced via Twitter that via Twitch.tv it will be streaming a special Nintendo "Treehouse" event, that, as well as the extended look at the final Smash Bros. build, will also include gameplay from upcoming Wii U and 3DS titles. You can probably expect to see footage from Bayonetta 2, Pokemon: Omega Ruby/Alpha Sapphire and maybe even the Wii U version of Super Smash Bros..
The stream will start on September 12, though Nintendo did not mention a specific time. Some Japanese fans have already managed to get their hands on a preview version of the game's final build at special Japan-only hands-on events, and some new information has already started to leak through.
I would assume that Nintendo would like to use this event to reveal any as-of-yet unannounced characters and features in the new game, so English-speaking fans don't have to turn to Japanese news sources to find out such information when the game launches this Saturday.