Great thread! I'll try and be as legible and ramble-free as possible. My short answer = NO. My longer answer is that, unlike Wii, the other two only financially settled-in a couple years ago. MS and Sony have been playing a real dicey game with their finances, this console generation. Things are relatively settled for both of them, now.
As for "power" etc - I personally wouldn't be surprised if cross-platform games (WiiU/PS3/360) only look a little better on Nintendo's new machine. If that turns out to be the case, then there's really no need for the other two to panic. I can see MS maybe getting nervous, it's been used to having the most powerful console on the market since 2001.
On the other hand, I couldn't really imagine Sony giving two shits if it's just a small difference. They suffered being graphically the worst-off between the three major consoles in the sixth generation. True, it was a relatively-small handicap compared to Wii vs PS3/360. But then that was the basis of my hypothesis of Wii U vs PS3/360, that it'd be a small difference in graphical fidelity, and that MS might crack in this situation, but I doubt Sony would.
If they're smart they're just quietly beavering away on their next offerings, with no urgently-imminent launch in mind. They'll probably have a goose at how The U fares when it hits the market.
Lastly, we must remember that the consumer of today generally hasn't the money that the consumer of 5-6 years ago had. Especially for stupid things like games. Double especially if they already have a perfectly good game system at home with reams of peng games they've never even played.
As I said elsewhere yesterday, I picked up both Dead Space games for my PS3 for really cheap. Had a demo of one ages and ages ago (I have almost no memory of it). Never really grabbed me, didn't buy the game. Now here I am, having spent the last three days wasting a lot of my free time on playing an old PS3 game from 2008 that I recently got for absolute pittance.
I think I'm touching on the same thing Jacob mentioned. There's just so much stuff to get. 360/PS3 are now entering that awesome stage of their lives where you can go into an establishment, and look at a big healthy wall of new games, and have a browse. New awesome games mind, because the developers can now make these consoles jump through hoops.
Of course, they're also now old enough to have a fucking massive back-catalogue. So along with the amazing new stuff, you can do that awesome thing where you go thumbing through decks of obscure pre-owned stuff, looking for that diamond in the rough!