Smash Bros. players with Nintendo's new hardware are in luck.
We recently learned that the 3DS version of Super Smash Bros. will not take advantage of Circle Pad Pro accessories. Instead, the new portable Smash Bros. will make use of the C-Stick built into the upcoming New Nintendo 3DS hardware.
I find this news awful because it gives Japanese players who buy a New 3DS access to a control scheme that allows for more tactical options within Smash Bros. It doesn't matter if you are a player that morally objects to the use of the C-Stick, the fact is that players who use it have an advantage.
The C-Stick gives players access to instant Smash attacks at a flick of the stick. Additionally, the C-Stick allows players to use reverse aerial attacks while traveling forward through the air. These examples highlight two basic ways having access to the C-Stick is useful, but there are more technical uses as well that might make your head spin.

In the past, the C-Stick has also proven useful for specific characters. For example, if the Ice Climbers grabbed an opponent, flicking the C-Stick made the computer-controlled climber unleash a Smash Attack without the player-controlled climber throwing their opponent. While I know the Ice Climbers have yet to be seen in the new Smash Bros. titles, it wouldn't surprise me if similar tactics were possible with a character like Rosalina and Luma.
This news also really bothers me because the game could have just been compatible with the Circle Pad Pro. It seemed like a no brainer from the start and it proves that Nintendo, sadly, isn't afraid to rarely support their officially released hardware accessories even when it makes the most sense.

Circle Pad Pro support for the 3DS version is something I've been hoping for since the accessory was announced. At E3 2014, I even suggested that the game take advantage of the accessory while playing it at Nintendo’s booth. Later, I was told by a Nintendo of America rep that this suggestion did in fact reach the development team. Basically, I tried my best to let Nintendo know that Smash Bros. enthusiasts wanted Circle Pad Pro support.
The bottom line is, shortly after Super Smash Bros. releases in the west, Japanese players who upgrade to the New 3DS will have a tactical advantage. So if we can play foreigners online, I am warning you to be wary because they may actually have more tools at their disposal than we will have until some time in 2015.