I think people that say Cafe won't be significantly more powerful than PS360 are retarded.

oh it will be at least 2 times more powerful but most of that extra power will be used for rendering 2-4 video feeds to the controllers, which is not a trivial feat especially if each feed shows a different view in a local multiplayer game etc.

All games won't be like that. So the extra power CAN be used for visual oomph.

... and rumours have been amazingly accurate at predicting Nintendo systems in the past?

Beyond the obvious failure to predict Nintendo previously, the rumours actually say very little about real-world performance and really only talk about what the system's components are based on. Being that the assumption is that these components are modified to suit Nintendo's needs, it is (nearly) impossible to make any claims of performance based on their loose similarities to other technology. After all, both the Cell processor and the Xenon were based on an outdated powerPC core architecture (Power3 IIRC) but after 5 years of modifying the core these processors don't perform anywhere near what you would expect from what they were originally based on.

I am bassing the power mainly on the sources that say around 360 level performance plus ubisoft saying that they will use PS360 level assets. All this tels me that real world performance including the possible overhead of the multiple displays etc is leading to games using PS360 level assets which the NGP is capable of using down rezed a bit. Even if the games are multiplatform I would imagine that the Cafe version would look and run significantly better.

As for the validity of the rumours, in the past Nintendo have kept their new hardware under very tight raps pre release but this gen they are pushing for more 3rd party support which means giving more outside people axxess to the hardware at a much earlyer stage and this enevitably leads to leaks. Obviusly not all will be correct and most won't be 100% acurate but I think we have enough information get a rough idea of the console.

If both consoles resemble one another in terms of "power", then it might happen. But i think it will depend on how successful both consoles are ad what type of games will come out for both consoles.

As for the next gen consoles, seeing as Xbox360 and PS3 are 5 years old at least, it`s safe to say that, at least, Wii2 will be better. But i honestly don`t know if the next Xbox or the next PS will be that much powerful than Wii2. What these last 3 generations have proven is that the winning console (sales wise) wasn`t the most powerful, so, you don`t need to have the most powerful console in the market to succeed.
I think that next generation there`s a high chance that both MS and Sony won`t bring overpowered consoles. Bringing a Xbox360 2.0 and a PS3 2.0 might be a safe choice financially since they could market their consoles at a lower price tag; still being superior to Wii2 and help keep game production costs from skyrocketing.

You don't have any idea AT ALL.

Until we see some tech demos or at least are told what GPU or whatever it has, you don't know the power of the console.

All the rumours have told us so far is they could be using an R700 GPU, which could mean a half generational jump (medium end R700) to a generational jump (high end R700). 

The only people who know anything are the ones who have seen what's under the hood of the console.

Well if you look at recent Nintendo consoles:

3DS - outdated hardware - 3D screen as mind catching gimmick

Wii - outdated hardware - motion controls gimmick

NDS - outdated hardware - second screen

Gamecube - powerfull up to date hardware - everything classic.

So if Nintendo can find something that would work as mind catching gimmick for Cafe I fully expect them to go with outdated hardware.

So the multiple roumers putting it's capabilities near the PS360 plus Ubisoft who have dev kitts saying 

"What we see is that we will be able to leverage a lot of the work we do for Xbox 360 and PS3 while we create games for the platform," Guillemot said. "So we will not have to redo completely the games that we create. We'll be able to use all the capacity the console is giving but also use all the work we do for the other platforms."

doesn't give us an idea of the kind of power the device has? The fact that every rumour about power has placed it near the PS360 gives us a rough idea of it's level of capabilities tells us that it will most likely be around that level, Ubisoft have dev kitts afterall so I would say they should know the level of power and they seem to think that they can leverage it's power with PS360 assets and engines which means that the rumours were right and that the system is around that level. Unless you think Nintendo sent out underpowered dev kitts so devs would think the system is less powerful than it is...

That says nothing about the system's power. Nothing.

It means the architecture of the console makes it easy to port PS360 games to it. That is all.

Nintendo used an architecture similar to the 360 because devs have an easier time with that one than PS3's architecture.