Those look awesome. I'm loving the first one. It's too bad all we'll probably see at launch is the white one >_< (Which is weird for me to be upset about since the Ice White 3DS is the one i want the most haha)
As for the name change thing it was probably just a rumor. If it was real though I'd be pretty happy. I've always hated the name Wii and Wii U. Bleh, NES6 sounds much cooler in my opinion, and might actually work in favor of Nintendo getting their hardcore gamers back.
Also, while the 6 does look a lot like the Dreamcast logo, i still think it looks awesome xD