NEC is a pretty cool company with a lot of great products. I am just not sure a new console would be a great idea. Their hardware was essencially "Haha! We have an NES that can out-NES the competition!" Similar to Sega, they just took what worked for Nintendo, expanded on it, and got a decent, but flawed result. Don't get me wrong, I'm not knockin' NEC. I just feel they should have studied the market more so maybe they could be in the gaming market today. I am baffled why no one thought the Super Famicom was coming.
That said, if they did come back, I'd expect some more original hardware, and more well-thought out marketting. I like a lot of things about the TG16 and the Turbo Duo. If they could actually get the third-parties on board, I wouldn't be against the idea of NEC re-entering the console market. My favorite thing about the TG16 was the fact that it felt like what the NES would have been had it not been marketted as purely a child's toy. TG16 had the tech, and style. You don't see many systems like that anymore.