TBH I suspect the reason Nintendo holds off on N64 games is so they have some to release in the future.... The Virtual Console will continue on the WiiU and the focus will probably shift away from NES and SNES games and toward N64... and maybe Saturn games will be added (and Dreamcast and GameCube would be awesome too, but I won't hold my breath on those)
Ultimately I (and likely everyone else but Nintendo) would prefer if they just bulk released games and left them there, so maybe within a couple of years of the Wii launch all the decent NES & SNES games and most of the decent N64 games (ie minus those owned by Rare) would already be out. I certainly wouldn't care if there hadn't been a VC release in the past 3 years if the games were on there anyway.
