I am curious about this scaling. Could a game like Skyrim be possible on Wii? If so what sacrifices would need to be made for the game to be played on it?

It's not just about the resolution of the textures. There are all the aspects of much more advanced AI, scale of the world, framerate, loading times and their frequency, etc.

Even greedy Capcom learned its leason with the horrible Dead Rising port which only had like 6 zombies in each zone. There won't be downports unless is kiddy games like Spyro and Lego.

I'm not sure what you mean by "(if not even less)" as Nintendo made that full 1GB available to developers and that wont change.  If it was to change at all, Nintendo would most likely open up some of the 2nd GB once they have their OS optimized and are pretty sure they would never need the extra space (after building in an extra buffer to begin with).

As for your question about a game built for 7GB being used on a system with 1GB.  First, your going to find that extremely few games during the life of the PS4 will have to use all 7GB of memory.  The ones that do would be more difficult, but not impossible to port to the Wii U.  A couple of sacrifices that would be made is less of the game in memory so there would be a more frequent need to load and the second thing I would image is lower quality textures.

Sony themselves have stated that not all games are going to be huge productions which is going to be true because the developers just don't have the resources to give every game a $100mil budget.  I would guess that 90% of the PS4 games released would be fairly easily ported to the Wii U .  I believe that most of the rest could be, but with a hit to the overall quality.

I'm finding that both of my sons and their friends seem to be into the more retro indie games lately, if that trend was to continue, all three 8th gen systems would have no problems.

In case of Skyrim they would need to get rid of many NPCs as they all have their own day/night cycle. Also the draw distance would need to be turned down drastically. Expect lots of pop ups.

Also the game keeps track of everything you do. That's why the framerate in the PS3 version dipped often when you're quite far in the game. Every dragon corpse, every item you put in chests, every NPC that has been killed, every decision that you made and more is recorded and put into your savegame.


@others
As for the CoD games, you should check CoD wikia. There are massive differences between the Wii version and the rest.
http://callofduty.wikia.com/wiki/Differences_of_Call_of_Duty_games_on_the_Wii

Extract:

All

• The graphics are not as well developed.
• The number of Frames-Per-Second is about 30 instead of 60, so lag is a bit more frequent.
• Killcams and final killcams are not in any games.
• Lobby Sizes are only 10 instead of 12.
• Because of this, Ground War is missing.
• Private match customization is more limited compared to other systems.
• No map packs or DLC is available whatsoever.
• Unlike other systems, an "Ally code" is required when adding friends to Ally List.
• The option to restart at the last checkpoint is absent.
• Split screen Mode is not available.
• No In-Game Host Migrations.
• No Third Person mode.
• The player can send text messages to your "allies" who are people that can be added as friends while online.

World at War

• Zombies is completely missing.
• Co-Op Campaign is also gone.
• Only 8 maps are available in Multiplayer. (All maps that have tanks in them are not there. Because of this, the Reconnaissance perk is gone)
• The "Black Cats" level is missing.
• Sniper rifles cannot be steadied by having the character hold their breath.
• Gore is not seen anywhere in the game, but blood is present.
• The game mode "Team Survival" appears as a Wii exclusive.
• Squadmate Mode appears as an exclusive, it allows two players at a time to play on a single screen. Though there are several limitations to it and what the second player can do.

Black Ops

• The campaign missions "Crash Site" and "Redemption" are shortened.
• Zombies is now present, but only Kino der Toten is featured.
• The missions "U.S.D.D." and "Revelations" are played as cinematics, and give the player zero control over the camera.
• The Valkyrie Rockets, Chopper Gunner, and Gunship killstreaks are all missing.
• Theater Mode is not supported.
• As with Call of Duty: World at War on the Wii, gibbing cannot be done, so there is less gore than the other versions.

MW3

• There are no Special Ops missions, however, Survival Mode is present.
• Like the PC version, Call of Duty ELITE is not supported.
• Theater Mode is not present.
• The Recon Drone, Predator Missile, Reaper, Osprey Gunner, and AC-130 are not present. (Though the Predator Missile is still available by means of hacking.)
• On the Prologue, and the cutscene after the mission Blood Brothers, instead of a controllable sequence, the entire cutscene is simply a video.
• No Gun Game, One in the Chamber, Team Juggernaut, or Drop Zone game modes. (Though hackers have hacked into the game finding them in hidden files and playing them in private matches.)
• No Community Playlist modes.
• The Hardcore Ricochet game mode is missing.
• The multiplayer maps are less detailed, with less patches of grass and objects like boxes and barrels.

Hardly the same games.

Like i said you either played some magical version or just have low expectations. Ive played those and there was slow, textures were messed up, pop in. and that was just SP mode. Online didnt run at 30FPS, there was input delay. All kinds of crap. You dont know what PS4 will or wont do. One could say ps3 games didnt the hardware either, but there are alot of games on the system that just couldnt be done on Wii.

Wow nice find. This was pretty much what I was expecting given the difference in specs. These games are severely gimped in terms of gameplay and not just graphics.

I didn't play any magical version. Framerate drops and texture pops are common in 7th gen games across all three consoles. (Hell, even Uncharted 2 had some pop going on) These aren't the worse examples I've played by a long shot. They were functional ports despite being designed for 512MB of RAM then crammed into 88MB.

And it's common sense that most PS4 games will not push the system. Most games on ANY console don't push it. High-end games today don't need even close to 7GB, it's logical that instead of spending the time, money, and manpower to max it out, a lot of developers will simply crank up the settings (like PC versions of PS3/360 games) and throw a lot of uncompressed/unoptimised data because with that much RAM you won't really need to compress/optimise memory-wise unless in most cases.

im just going to refer you to Barozi's post, look at that list and then try to tell me the Wii version was like the others

We are not talking about quality of games but their portability to other systems with less power/resources.