At least 2 times as powerful, Wii U needs to find the sweet spot where the developers like it. I think that the other next gen consoles might end up too powerful and developers would not justify bringing much games to them. The same thing for consumers, they would not justify spending $70 on a game new. Since Wii U is at 60$ a new game it is at a good spot for consumers used to spending 60$.

It's more powerful than PS360, but not much. Nintendo knows how to program for their own console better than any third party ever will, but most of their games don't push the system's capabilities very far. Wait for Zelda, Smash Bros, Retro's game, or Monolith Soft's game to drop. Then we'll see what Wii U can do.

He made a joke... I made another joke... that's it.

In fact the Wii U's CPU is 3x Wii CPU's with more clock, cache and some others little features but the core is the same CPU.

Can someone explains all that stuff to me in simple words? preferably using a DBZ power level comparison

I went 1.5x. Based on what we now know, the GPU is quite a bit more powerful and capable and the double RAM should do wonders (2-4 times).

The problem/bottleneck will come in games/engines that use a lot of the CPU power or need faster RAM. Although the architecture may be updated from the older CPUs in the 360/PS3, the mere fact it is clocked so low will hinder some games.

So overall, 1.5x seemed fair.

WiiU = over 9,000

PS360 = 4,000

On the GPU side (depending whether it's Redwood LE, Redwood or Turks based) some 1.5-2x stronger.
On CPU side, most likely 1.5-2x weaker. (both compared to 360, PS3 is bit trickier to measure)

Not that it matters to 1st parties, but it might for 3rd parties, and consequently to some of people owning it (for example, if major 3rd party games like GTA VI or Elder Scrolls VI are not possible on WiiU or look much worse than on MSony next-gen offerings).

Is there a link to Nintendo officially announcing Wii U's CPU as being an up-clocked+up-cored Wii CPU?

So that means that PS360 is Nappa and WiiU is Goku from the Saiyan Saga right?

Correct.