Not only did the handwritten (more or less) invitation say "Note the date," so did a Samsung tweet on the company's Twitter account.
The company will be hosting a live-stream of the event on YouTube at http://www.youtube.com/samsungmobile.
Despite the fact that the devices sort of defined the phablet segment of the market, with some ridiculing their large screen sizes, they are no longer the biggest in Samsung's line-up, with that place being taken by the Galaxy Mega. In addition, this year's flagship device, the Galaxy S4, has a 5-inch screen size, meaning it's starting to impinge on the Galaxy Note's territory (the current version, the Galaxy Note 2, is 5.5-inches in size).
Thus, the Note's screen size is almost becoming typical, rather than outlandish.
There is some speculation that the company will use the Sept. 4 event to launch the smartwatch it earlier confirmed it was working on. However, Samsung is also holding a second event on the morning of Sept. 5 that my include the smartwatch as well as new laptops and perhaps some other Windows 8 devices.