Another piece of evidence to add to the pile that NX will release at the end of this year.
On a second point, though, I'd say it's also an indication that the home NX will be $300 or less. Generally the logic of keeping your previous gen console around when your new one comes out is that it's a couple hundred dollars cheaper, so you can sell it to an audience who just want a cheap console with a decent library, and don't care about having the latest and greatest.
This logic doesn't work if your old console is only $50-$100 cheaper than your new one, though, and with the current trajectory of Wii U prices, it's unlikely they could bring the cost of it much below $200 to $250 by the end of the year. This would be fine if their console were $400 plus (and indeed that's around what PS3 and XB360 were selling for when PS4 and XBO were released), but with a new console in the $300 region it simply doesn't make sense to keep the old one around. You're just cannibalising sales of the new console and confusing customers by keeping the old console on store shelves.