No offence, but I think its obvious many people here don't have technical know-how in terms of how a processor and GPU work with RAM.
Devs cannot build a WiiU game the same way you would say a PC version or an xbone or PS4 version. As a developer, you sort of have to pick which system you are truly focusing on, and then make fast ports to the rest (or conversely have a separate team build the game multiple times for each platform). Because the ps4 and xbone are very smilar in how they operate from an architecture standpoint, they will pool resources into it.
For the WiiU though, the way you design a game has to be different. If you try to load everything into the processor and just use RAM on the side to dump sprites and the GPU just for certain graphic rendering is poor practice. You will find going forward that all games made by nintendo will be gorgeous because they will optimize their build to get the most out of the system. It isn't even close to the xbox 360 or ps3 (and people who have made comparisons seriously don't understand computer architecture).
If we just look at the PS4 and wiiU processor you are only look at about a 30% increase in power. An in fact, this number is inflated because anyone who understands how gaming works knows that having 8 cores isn't technically that much better than 4. Games are built around 3 or 4 cores, they don't really have a use for going more than that (heck only games like crysis 3 use more than 2 cores). It requires complex programming and isn't always worth the effort. The PS4 and the xbone need more cores because of how much multi tasking they do, and this is why they also have much more RAM. They will be heavily multitasking so they will use the extra cores. But the WiiU wasn't designed the same way, it is meant to primarily be only a gaming device so it doesn't need more than 3 cores really.
The area where the PS4 really shines though (compared to Xbone and WiiU) is in its GPU. We are looking at maybe 5 times the teraflops over the WiiU. What realistically this will mean is a heavy use of physics in PS4 games. However, much like the issue with WiiU, how many devs will actually use it? So I expect, much like with the WiiU, only Sony will really capitalize on their GPU by using their own studios to build around it. AAA titles that are not exclusives will probably just build around the lowest common denominator (ie xbone).
I don't think people need to worry. Games on the WiiU will look phenomenal. If you really want the best graphics, go PC obviously. Consoles are really for couch-gaming and exclusives.