I haven't used every other service out there so I can't really comment on whats missing, but we can suggest what it should have and maybe how it should work.
Here's how I think it should work;
You get your 3DS, you connect to the internet and it immediately ask you to either log-in or create a My Nintendo account.
You attach that system by serial number to your account, and now no other account can register your 3DS as long as it's attached.
-you can also unattach your 3DS from your account should you upgrade, sell or lose it, which would mean that the next time that system goes online, all unauthorized content would automatically be deleted(and/or deactivated) since it's not activated for that system anymore. (games can be activated again with an account that has already purchased that content)
All the content you buy from the Nintendo Online Store is all attached to your account and can be moved to any device attached to your account, but you can only have 1 3DS attached to your account at a time (unless it's a family account)
You can share a demo of a game with another 3DS without needing an internet connection. From retail or DD game or downloaded demo. All demos are shareable between 3DS.
*You also have the option to back up and use any save from any game on your 3DS to your online account. (cloud saving) so that if you do get a new 3DS you can pick up where you left off the last time you played while connected to the Nintendo Cloud.*
Inside your account is very similar to Steam
You see a pic of the boxart, a description of the game, a video of gameplay and an online manual.
you also have the option to check for updates (DLC, new maps, etc. etc.) for your game.
The system will automatically recognize what is installed and what is not installed on your system and give you the option to manage your active and non-active games
Credit Card info can also be saved to your account or points can be pre-bought and stored on the account (not the system) to be shared with other system (family account or Wii2)
First time you put a game in your system, and you click to the icon to play it (like Disc Channel) it will give you the option to Play, Install or Register (game is tied to your My Nintendo Account and that info is also saved on the game card)
-Can only install a game after it is registered and tied to your account, then game card only works like a demo until you uninstall the game from your system and/or unregister the game from your account.
There will also be a Friends-list that you manage through your online account that goes by USERNAME since everyone will need an account to go online.
-But someone cannot be added to your "Active" Friendlist without their permission. (JoeBlow123 sends Friend Request - accept or deny?)
From this friends list you will have the option of text, voice or video chat that is completely independent of anygame you are playing and you can continue voice chat through any game or other function on the device (text and video will be limited to applications that can support them since text requires a keyboard and video requires the camera and a screen to view)
From this friends list you will also be able to not only see who is online, but what they are playing and then either join or invite them into a game.
On the home page, which will probably be pretty similar to Wii's only more customizable (size, color and background pic & music), there will be notifications of NEW stuff on your system.
You turn on your 3DS and The DEMO channel is flashing a new stuff you've never seen, so you click on it, Demo Channel loads and you select one of the 4 new demos that instantly loads up to play (it downloaded automatically to a dedicated section of memory on the 3DS). When the demo is over, it ask if you'd want to buy that game and then direct you to the 3DSShop if you want.
Back on the Main Menu the 3DS Shop is flashing with a 20% Off Summer Sale sign scrolling past.
you click and find certain titles to be on Sale or price reduced and ready to download.
Gifting is also an option
That's all I got for now. Anyone else got any idea how they would want online to work?
You can add to mine or show it's flaws, but what do you think? Where is there room for improvement? What would make you say Wow?