As of now, the game has been in development longer than (I believe) Melee and Brawl prior to the reveals of their trailers. I doubt this event will yield much of anything, though how awesome would it be to get the trailer out of the way here, and give the alleged demo facetime at E3??
hmm... let me check...
Brawl's development began in October 2005, and we got a trailer at E3 2006, in May of that year... I remember it well, six years ago... time surely flies...! anyway, from October 2005 to May 2006 are 7 months.
SSB4's development began after Kid Icarus: Uprising's ended development, which we can assume either as February or March 2012.
so, we are already at December 2012, as such if we assume the development began in February, SSB4 has already 10 months. if we assume March as the beginning, then, development has already taken 9 months.
conclusion: SSB4 has been in development for more time between Brawl's start and Brawl's reveal at E3.