@ Hab
Brawl was in development for a bit over 2 1/2 years with a full time staff of about 100, and dozens of outside contributors (literally we got that many contributors from outside sources for music alone). A 2014 release, at the latest (as in December 2014), will mean these two (not one) games were in development for about the same period of time.
Granted, most of the Brawl staff was Game Arts (who are a C-grade company) and people who had no prior fighting game experience. However, the technology used for the Wii with Brawl (minus a few motion sensor-related things) was virtually identical to the GameCube.
Unless the Smash 3DS and especially the Smash WiiU staff is already fully trained with how to make games on the 3DS and the WiiU (hint: they haven't made games for the WiiU yet), it's going to take longer. Unlike the Wii, the WiiU is actually a new console, requires dozens of employees to either learn new technology or get dropped from the project.
I know the Namco Bandai staff working on Smash WiiU and 3DS is one of the premiere staffs in the fighting game industry, but even they can't do that. They are dealing with new technology they haven't dealt with before (especially graphic related [which I can't wait to see]), a brand new console (instead of a GameCube with motion controls that were largely ignored in Brawl), this is their first crack at the bat with smash, and to top it all off, they're making 2 games on 2 completely different consoles.
I don't know about you, but knowing that, a 2016 release seems to be more and more likely. Initially I was expecting a 2014 release, and as of the past 6 or so months I've been saying 2015 is most likely, but the more I think about it, the more a 2016 release seems to be the most likely, as well as the most ideal for everyone (especially if this game looks, plays, and is as amazing as I am visualizing).