To me, what he is saying is: "ok, there already exist two HD machines on the market who had all the impact to themselves. Now, with Wii U, Nintendo will fail to impress gamers in general because HD has already been done."
This is true. But now, it`s only one side of things, because PS4 and Xbox 720 will still be in HD with better graphics. So, in a sense, if HD won`t work for Wii U, it won´t work for Sony and Microsoft`s new consoles as it did with Xbox 360 and PS3.
Will they be that much powerful to still impress? No one knows. Personally i think they won`t. I see it, as many have pointed out, as PS2>GC>Xbox.
About Nintendo Wii U`s power, i read in an article where some devs think that it will have 50% more processing power than PS3 and Xbox 360 - http://www.industrygamers.com/news/wii-u-is-actually-50-more-powerful-than-ps3---report/
Pachter`s mistake continues to be that "power" sells consoles. PS2 and Wii weren`t the best and just look at their sales.
"Pachter says he believes Microsoft and Sony will continue to reduce the price of their consoles going forward, and if the Wii U is too expensive compared with those alternatives, it could be in for trouble."
That didn`t stop both PS2 and PS1 to be generation leaders despite having cheaper consoles on the market when they arrived.