No advertising yet. I mean, I get it, there's issues, but keeping it so secret? Why? Wouldn't it be better to start making teaser commercials, building hype, up until March?

Whether if it is going to be released December or March, no advertisements still is ridiculous. Even teasing the outline and putting the motto of Nintendo is enough to build attention towards them.

What could  Nintendo possibly be planning?

We're are 1 year away, there is plenty of time for what you are asking! Best time to start is on holidays... (December)

Lol so advertising for a console that launches in 11 months.
Did you see advertising for the xbone and ps4 December 2012? 

Damned if you do, damned if you don't.
If you aren't advertising a long time in advance "They're starting advertisements too late, how will I get hyped? I need years"
If you advertise a long time in advanced "Why is it taking so long for the system to come out. It's releasing way too late to matter anymore."

Remember when Nintendo started pushing the Wii U a year and a half early? Yeah.

Give it time. They'll probably start in August or September and then roll up the marketing like hell near January, right after the holiday rush is over.

I am expecting a September - November event that will kick-start the official hype train for the NX.

If we follow the same pattern as he PS4, the NX will be shown in June so at E3, most likely.

It wony be at e3

I am worried about NX, but it has nothing to do with lack of marketing

PS4 was announced only 9 months before launch. In its own conference. Xbox One was announced just over 6 months before launch. Both sold well enough at launch. So long as they announce this summer - that is, between May and September - they have more than enough time to promote. It's about the aggression, that's what they need.