That's the eternal question that really doesn't matter. If he wants a PS3 at this price, but did not want it at a prior price, what is the problem? Not everybody dictates their purchase decisions on "what is the most powerful device at this moment".
Well aside from that, once the wii U is released the other consoles will be deemed "obsolete" and you'll be able to get them even cheaper or m$ and sony will feel threated and release the new consoles they are obviously sitting on and you'll have just paid a decent amount of money for last generation's console.
A) I like Nintendo and all, but Nintendo and Playstation, library-wise, are two separate beasts. If someone wants a PS3, telling him to just wait for the new Nintendo is like telling someone who wants a new car to just wait until they come out with the 2012 line of mopeds. (Not to imply one is better than the other - you can swap the car/moped assignment if it makes you feel more comfortable.)
B) As someone who still plays his Commodore 64, NES, Genesis, Playstation 1, etc., I believe consoles are NEVER obsolete.
C) For the foreseeable 12 months, a PS3 is a better buy than a Wii-U considering the former has an established library while the selection of Wii-U will consist of launch titles and older Wii games (that you can play on a much cheaper Wii). (rlemmon already covered that fact)