Hoping for the revealing of the newest Nintendo first-party games(excluding Kid Icarus), as well as possibly some new free downloadable software.
Probably Pokemon. It has to be pretty damn big. They wouldn't do this for Luigi's Mansion 2, Animal Crossing, etc... Pokemon and Mario are actual system sellers. As much as I love Animal Crossing it would never be that big of a release for a hype message to be sent out through Swapnote.