Even if all those significant steps "fail", they'll surely better Wii U sales a little, enough, with successive regular 1st party releases, to grant it 25-30M in its first five years and a half and 30-40M lifetime. Very disappointing, but not a killing blow for Ninty, not to mention that it could further better later. Rushing the development of the next home console woudn't be justified anyway and it's actually the very choice that could put Ninty in serious danger.
Ninty could lower costs and attract potential users that find the pad too large releasing a version with a 5" display pad, although it's too late to correct another error, slower and smaller than competition RAM, that can make ports of the largest multiplats first developed on PS4, XBOne or PC difficult.
About the last issue, I guess Cerny and the whole PS4 team must still be thanking God for the intuition (helped by dropped prices) of doubling the initially planned 4GB amount of RAM.







