So, I got overhype by learning 2 dates one of them is a round anniversary and is VERY soon. The other is direct speculation and less relevant since the number isn't round.
Paper Mario -> release date JP -> August 11 2000
Source:
http://www.mariowiki.com/Paper_Mario
It's on a Monday and would be the 14th years. Why I think it deserves mention is because...
POTD day, weeks of probable direct or the next week and is referencing the birth of the series itself since it's the first game.
But the next one sounds scary (not for newcomer but I'll tell after).
Paper Mario: The Thousand-year Door -> release date JP -> July 22 2004
Source:
http://www.mariowiki.com/Paper_Mario:_The_Thousand-Year_Door
It's next Tuesday as of this post and it would be the 10th year. You also have to remember that this is by far the most appreciated game of the series followed by the first one so it's relevant. The number is perfectly round and it happens on POTD day which means that it can't be newcomer but remember that a popular stage idea exists that is from TTYD so it could have reveal potential.
Quote this for your answer if you want those dates in the list.