I disagree with you here.  I know a lot of core gamers and casual gamers who both think that price plays a major role on what system they get.  When considering a system, a high price point can be very intimidating.  Especially when you stack them up against options that are literally hundreds of dollars cheaper.  If we have the Wii U drop to $249.99 when the PS4 comes out and it's $449.99, a lot of people will hesitate to buy the PS4 when they see this huge gap in price.  They'll naturally go for a cheaper option that is still relevant.  This wont apply to everyone, but I know this goes through a lot of peoples' heads.  Before I was an avid gamer, when I looked at systems this is how I thought.

Don't think so
The price won't be a problem - I know most casual gamers don't study that stuff like some people might but they have eyes.
They see how much bigger the gap between the PS4NextBox and WiiU will be.
Sony and Microsoft will advertise the crap out of their consoles and im pretty sure the games they will advertise will look even better than what they have shown at the Sony presentation(cause they used old DevKits with only a piece of the power of the actual PS4).
They see the WiiU won't get the games most of the gamers even casuals want - The console is getting PS360 ports and most people don't need a WiiU for that aka a console that is still more expensive than those 2 and only looks slightly better.
The big jump and increase in graphics of the PS4NextBox will get the attention even of the biggest Casual and convince people to put out 200$ more than they would pay for the WiiU.Most people think PS4NextBox will cost 2389723$ but those consoles will be cheap for what they will offer.
People won't hesitate to cash out 400$ for PS4Nextbox cause those are the only consoles where you can get most of the games people are interested in.

External HDD support is great but the internal space has to be big from the beginning.
Cause it doesn't stay with the price you pay for the WiiU - You have to cash out even more for it and then you are  closer in price to much more appealing consoles.

Don't think so
The price won't be a problem - I know most casual gamers don't study that stuff like some people might but they have eyes.
They see how much bigger the gap between the PS4NextBox and WiiU will be.
Sony and Microsoft will advertise the crap out of their consoles and im pretty sure the games they will advertise will look even better than what they have shown at the Sony presentation(cause they used old DevKits with only a piece of the power of the actual PS4).
They see the WiiU won't get the games most of the gamers even casuals want - The console is getting PS360 ports and most people don't need a WiiU for that aka a console that is still more expensive than those 2 and only looks slightly better.
The big jump and increase in graphics of the PS4NextBox will get the attention even of the biggest Casual and convince people to put out 200$ more than they would pay for the WiiU.Most people think PS4NextBox will cost 2389723$ but those consoles will be cheap for what they will offer.
People won't hesitate to cash out 400$ for PS4Nextbox cause those are the only consoles where you can get most of the games people are interested in.

External HDD support is great but the internal space has to be big from the beginning.
Cause it doesn't stay with the price you pay for the WiiU - You have to cash out even more for it and then you are  closer in price to much more appealing consoles.

The type of memory that the Wii U/iPod/Ipad etc.. uses is not "pretty cheap".  You can buy a 1TB external hard drive for less than what Nintendo would have to charge for 64GB flash installed in the system.   What is everyones problem with the external hard drive?  Why would Nintendo want to charge every single person who owns a Wii U for something that a lot of them would never use?

I have seen a thread about Lego City: Undercover being 22Gb to download, but because the Wii U hardwae has 32 and 8Gb of solid state memory, it seems to be a hot topic and an oportunity to again dismiss Nintendo's hardware.

Now, the PS3 and Xbox360 both have removable hard drive, relatively easy to change. For the PS3, it is just necessary a screw driver, while the 360 doesn't need anything. The only downside is that you need a propietary hard drive to replace the existing one, but these are known to be more expensive than common ones. It is possible to use a non-propietary hard drive for the PS3, but you have to be sure it has the exact dimensions as the original. Not a deal breaker, but not as easy as to buy any external hard drive and pluging in it on USB ports.

None of the methods these 3 systems use are that much different from each other. In context, I say it is better if the system comes with a relatively small storage memory, then the user can buy, once, an external hard drive with the capacity needed. I don't really think it is the best option to charge the user with a 500Gb hard drive when in just a year, it is possible it needs a new one; while for example with the Wii U, I can buy up to 2TB cheaper than buying a system with it (it will last more than a 500GB for sure). 

Added to these, Nintendo decided to sell all their frist party software on the eshop, while still selling retail copies. If the game is bigger than what your system can store, you get a retail copy. If not, for sure that user wanting to download the game, have an internet connection to buy the game from online stores. 

Nintendo states that in the future it will be possible to plug two hard drive to the system at the same time, and even transfer your files from one to another if you need more capacity. 

What do you think is the problem with Nintendos desicion about the storage memory inside the Wii U?

The only problem I see if the next generation of system, will try to use Cloud storage.