Nintendo of America has joined Nintendo of Japan and Nintendo of Europe by saying this on twitter:

“We’ve got some news to share 2nite around 8:30pm PT. Be sure to check back to get the latest!”

Update 3: Some more details from AndriaSang about the Swap Note and other hints at info tonight:

It’s Iwata standing next to a giant Kirby plushy. The text asks people to tune into the broadcast.

The appearance of Kirby in Iwata’s message has caused speculation of a possible Kirby-related announcement.

 

A few other creators have provided hints about what to expect from the broadcast. Masahiro Sakurai, head of the studio that just completed work on Kid Icarus Uprising, said via Twitter to expect some sort of news related to Uprising. (It should also be noted that Sakurai is one of the main forces behind the Kirby franchise.)

Masanobu Suzui, head of Theatrhythm Final Fantasy developer Indies Zero, also suggested that fans be sure and watch the broadcast.

Update 2: Picture of a SwapNote that Iwata sent to Japanese 3DS owners that could indicate some Kirby related news:

Update: NoA had this to say on their facebook page:

“Wondering how you’ll understand tonight’s Nintendo Direct since it’s all in Japanese? Don’t worry, we’ll be sharing North American related announcements (in English). Check back here and on our @NintendoAmerica Twitter around 8:30 PM PT to get all the news.”

This doesn’t confirm that NOA will do a stream event, it just says they’ll have news about 30 minutes after the Japanese Nintendo Direct starts.  So could just be rementioning of Japan’s announcements, but stay tuned tonight to find out for sure!

Update 4: 

Nintendo of NA has confirmed they will not be doing a NIntendo Direct tonight.

‘While there will not be a video specific to North America, we will be revealing info this evening and through the weekend.’

Link