Sakurai would be hard pressed to surprise us at every damn reveal, Direct or otherwise.I am not entirely sure, but I would be disappointed if we didn't. Tropical Freeze is one of the biggest releases this year (so far) and the other big releases do not have a potential for reveal (like Yoshi, or maybe Wario with Mario Kart). That being said, we could get a second Mario newcomer or something. This, the first Direct of the year, would be the perfect time to reveal something and again, Sakurai mentioned the Direct. If I recall correctly, the only time he did that was in regards to Rosalina. So I am expecting a newcomer, Diddy is WAY to obvious in my mind. There is no aspect of surprise.
Surprises are nice, but getting the expected is just as good, I find, as it means one less unknown to worry about. So bring on the Diddly and whoever else, I say.
*sips tea like a bosse*