the wiiu's first 2 weeks were 430k, the wiiu wont sell 430k combined in dec/jan/feb of this/next year. I would not be surprised if the ps4 can sell 400k in 2 weeks, its performance after those 2 weeks will depend on any followup releases.
It is not a delusional proposition at all.
Sony can sell more than 400k on day 1 if the over 1 million preorders number is true.