Its even hardly a gimmick, they already did that with the DS with Ds lite and Dsi.
If a company keeps selling the sanme product of course it will cause a saturation point. If not, then we still have the sane ipods at launch for years. But we knew what happened, theres ipod nano, shuffle, video, mini and the original ipod and of course different drive space.
end of core gaming days prediction:
E3 2006-The beginning of the end. Wii introduced
E3 2008- Armageddon. Wii motion plus introduced. Wii Music. Reggie says Animal crossing was a core game. Massive disappointment. many Wii core gamers selling their Wii.
E3 2010- Tape runs out
http://www.fivedoves.com/letters/march2009/ICG_Tape_runs_out.jpg