"Nintendo faithful" are kinda dying off I think.
That would be I think people who grew up with one of the following systems -- NES, SNES, N64, and maybe GameCube as the last one. The GameCube was 12 years ago now, so even that is a long ways away.
Every gen cycle you'll lose some of these people as some of them are now getting into their late 20s/30s and there are more important things in life at that age than video games.
The kids who grew up with a Wii aren't as loyal. The Wii had broader appeal as a console, but I think it didn't do as good of a job of creating "Nintendo lifers". Nintendo pushed Mario and casual games hard, but I don't think they did as great of a job on the Wii in getting kids to fall in love with other IP, like the N64 or GCN even did.
That and a lot of Nintendo fans simply make a big fuss on internet forums but then don't put their wallet where their mouth is. Like that Phenom08 guy who was probably the most rabid Wii U fanatic on this board, but didn't actually have the system himself.
I think $300-$350 is too expensive, some Nintendo fans are probably used to paying $250 max for a console.
