Nintendo has never initiated the release of 'next gen' consoles. SNES came out years after Genisis and other sytems. N64 came out a year after ps1, gc came out a year after ps2.
The real question should be when will MS put out a new system, as they are more likely to do so than any other company. I know I have said in the past that within 3 years we will see a WiiHD, however, I see that more as a DS to DSL change than a new console. I think that will be more of a firmware thing than hardware thing. Possibly with a better sensor and new HD firmware, upto 1080i probably.
Back to MS, I see them keeping the 360Elite for 5 years. Thus, in 2011 we will see the introduction of a new xbox. Then by 2012 a new Nintendo product with a different name (as they never use the same name) and possibly a new PS4.
Also, for the LTD of systems, 30m for 360, 40, for ps3, and 80m for Wii/WiiHD by 2012.
