I knew this already

Well then you probably never took the time to think about this topic, as your previous state of knowledge made no sense.

4.7GB for next gen disks ?  That's just impossible. How would developers be able to put Assassin's Creed 3, Mass Effect 3 etc. on the system ?
Double layered disks as Nintendo already did with Smash Bros Brawl ? That would theoretically work RIGHT NOW, but obviously not in the future. If WiiU used the DVD9 format then third party publisher support would already be at zero. There's no way to keep franchises like Assassin's Creed, Batman Arkham and Call of Duty alive on the system, so trying to build a fanbase would be completely pointless.

Of course. It's Nintendo Ray

If not counting first party only, you can add Samurai Warriors 3, Sakura Wars So Long My Love, and Raving Rabbids Party Collection to the list :b

The WIIU is positioned as next gen, but here again it doesnt compare with current gen, PS3 does hold 50G on a bluray.

Also WiiU doesnt have a blu ray drive so you can not play HD movies on it inthe standard format for that.

These are factual points.

Its derived from a Bluray disc what do you expect, DVD capacities ?

The Wii U could hold 50 GB on a disc if it is dual-layered exactly like Blu-rays. The only diffence is that it doesn't have licensing to play movies.Also unless you are a movie fan, physical copies of movies aren't necessary when it has all the major streaming services.

I'm hoping for a new N64/GCN-like Paper Mario, Super Paper Mario was awesome (and I actually liked it more than the other 2 games), but it didn't have that great turn-based battle system, Sticker Star was a good game, but compared to the series, it's meh...
the reason I brought this up in this topic is because, the Paper Mario games aren't very graphics heavy if you haven't noticed (XD), so coding the graphics wouldn't take a lot of space on the disc compared to graphically rich games like the upcoming Monolith Soft X, so that leaves a lot of place for big worlds and stories, I'm interested in what Intelligent Systems can come up with

I bought a launch model Wii on release day back in 2006, bought Brawl and Prime Trilogy, and Xenoblade, never had a single loading issue with any of them. Used the hell out of my Wii for six years.

If I remember correctly, the dual-layered Wii disc issues was quickly remedied by Nintendo following the Brawl launch. There were suddenly over a million people with dual-layered Wii discs and those types of discs are more difficult for DVD-writers to read, so any amount of contamination over or around the lens can make reading the disc difficult or even impossible. Nintendo heard all the issues and released those nifty little Wii lens cleaners.

Wii U discs hold 25GB on a single layer, just like PS3's Blu Ray. Dual layered could therefore match 50GB dual layered Blu Ray. So yes, it does compare.