What was Nintendo TVii?

Whatever it was, good riddance. The name is too similar to the Vii.
If you don't know what the Vii was, look up ashens' review of it. It's gold.

The beggining of the end.

Oh my, I'm simply so saddened by this! I can't believe it...

A lot of people rip on it but, it was pretty fun with sports. Those interacting polls and games... I liked it.

What was exactly Nintendo TVii?
I never used it.

Used to love it but then they quit putting in any effort. I quit watching. Good memories, though.

I logged in once, closed it, and never opened it again :D

I set it up and never used it again after that, so I don't mind if they are getting rid of it. 

You should update your firmware if you still have that icon... 5.4.0 removed in in last month in Europe.

... I see that's it's already retroactively gone for us Europeans, thanks NoE you are the best!