Nintendo, or some overzealous uber-creepy fan, called press from an unknown number teasing Wii U.
http://www.nintendoworldreport.com/blog/30390
UPDATE: So this might have to do with a mysterious postcard some NWR staffers got last week about Medium, a game apparently by Bloober Team. The Wii U in the phone call might have been Medium. I guess maybe we will find out soon enough.
The original post is below:
Earlier today, I got a phone call from an unknown number. I normally don't answer calls like that, but I figured "eh, why not?" and answered.
"Hello?" I asked. I heard some muffled noises on the other ends. It was extremely faint. I repeated: "Hello?"
"Do you know about Wii U?" The odd voice on the other side said. "If not, you will."
To be completely honest, I wrote it off at first, thinking it was someone pranking me. I checked Twitter and saw other Nintendo-covering journalists also sharing the same weird phone call. Then I realized that Nintendo is engaging is some weird, freaky viral marketing for Wii U.
Hours later, Nintendo announced the Pre-E3 Nintendo Direct, airing at 6 p.m. EDT/3 p.m. PDT in North America, and similar times across the globe (10 p.m. UTC).
Fasten your seatbelts, gang. It is about to get crazy.