That does sound in line with every video Nintendo showed at the E3.
Each time they showed several people playing on the Wii U in the same room, only one of them had a Wii U controller ( and on some noone was actually using the Wii U controller, it was just displaying additional information for the game).
My guess is that there are technical limitation in terms of streaming data to more than one controller as well as displaying it on the TV at the same time. There are probably issues in term of cost of the controller ( I would hazard the new Wii U controller isn't going to come cheap if you want to buy an extra one, I would guess the controller sold alone will probably be around 100$).
PS3-Xbox360 gap : 1.5 millions and going up in PS3 favor !
PS3-Wii gap : 20 millions and going down !
