I think most of you got the wrong idea here. I'm not saying that the Shield tablet is the better buy. I'm saying that the Shield tablet wit full hd screen makes the Wii-U with it's controller only tablet look like a poor design choice for the same price.

What i'm saying is a "Nintendo Shield tablet" would be better than the current Wii-U.

The Wii U will have games and content you cannot get anywhere else. The Nvidia shield tablet will have nothing but third party ports and content that will also be available on multiple competing devices. This will also mean that very few games and apps will take full advantage of the Nvidia Shield's capabilities.

On a side note, I think if any console maker wants to stay in the console business, the exclusive content and ease of use will be key essentials. Lately, the PS4 and Xbox One have been losing exclusive content because they are basically PC's themselves, which makes porting games much easier than it used to be. Also, because consoles have gotten crammed with all this multimedia content, which can be done better on other devices, they've become clunky and overly complicated while PC's have become easier to manage than before. This needs to be fixed.

This is indeed the last generation of consoles. Soon we will have PS4 specs at the same or lower price as a PS3. Tablets, phones & TVs will all have the same power as consoles engineered a couple of years ago (5 or 10 year-generations are a thing of the past). Consoles have survived because they could provide relativly good specs for a relativly good price - with software adapted to the format.
Hopefully Nintendo will survive as a provider of software.

One mistake, for storage, you noted that the Nvidia thing can be expanded using SD cards, but failed to note that the Wii U can be expanded with hard drives.

"All of this will run you $299 for the 16GB WiFi model or $399 for the 32GB LTE model. You are also probably going to want to pick up the new SHIELD Wireless Controller for $59 and perhaps the SHIELD cover for $39. If you total the base model up with the controller and the cover you will come to $397"
http://androidandme.com/2014/07/news/nvidia-shield-tablet-full-details-leaked-arriving-july-29-for-299/

Hard drives, SD cards, USB thumb drives, SSDs, etc.

Removed the SD part, as it's not provided with the $299 package. Though since SD cards are internal storage it's a bit different from a hard drive(you're not going to carry around a hard drive with a tablet if you want to play on the go). Also i'm not sure on what media you can store Wii-U games?

well one is nvidia selling something with nvidia chipsets in it. So the low price is kind of given as there is no markup.

If Nintendo were to release the exact same as the shield there be a markup cost that Nintendo pays Nvidia for in top of that price.

Also Wii U come out almost two years ago, so I would expect tech to be caught up considering that Wii U is practically last gen.

True but Nvidia can only make money on the hardware, so that price probably contains a decent profit margin. So they should be able to get break even with that price(not even sure if they manage that now with Wii-U).

Also they would probably opt for a smaller screen with a lower resolution(Wii-U games are mostly 720P anyway). This would bring cost down further and improve battery life(or go with a smaller battery wich would make it even cheaper). The also don't need two 5 MP camera's etc.

So all in all they should be able to sell such a system for $299 with a small profit, and make some extra money on custom SD cards(not as expensive as Vita please).

The shield tablet is for now the only tablet that can reach console graphics, most tablets are still leagues behind. That and the shield still has the disadvantage of running Android. If it would run android and steam os, then it would be a real threat (but still not to Nintendo)