There are still so many unknowns at this point that a lot of what is stated here is speculation, but I'll play along. Let's assume that the Rev does hit sub $200. Let's assume the Rev's power is closer to Xbox 360 than to Gamecube--i.e. closer to the next generation than the current generation.
Now think about a potential consumer. You have a well know brand (Nintendo), well known games (SMB, Zelda, Metroid), and a curious controller all for ~$250 (console plus one game). That's almost an impulse buy, not quite but almost. For 360 and PS3, which will cost over $450 (console plus one game), most people will think long and hard and actually save money before picking up the console. What I'm saying is that for $250 or possibly cheaper, you'll get more people saying, "It's Nintendo, it's Mario, it's Zelda, I want to try out the controller, why not?" This is just anecdotal, but many people I know decide to buy things like an iPod with just one or two weeks worth of decision time since it's "only" $200. They never talk about it then one day they just show up with an iPod. What's that magic price for the majority of consumers to consider somehing an impulse buy? I don't know, but $250 vs. $450 is a big margin. Don't underestimate the impulse and semi-impulse buying crowd. Many will say that is the very crowd that made the NES what it is and made Nintendo to be the company that it has become.