Smash Bros is a horrible example because they are entirely two different games, the latest Mario vs Donkey Kong is a better example since they are the same game and it does allow cross-buy.

Think of it like Vita/Vita TV, do u have to buy 2 seperate versions of the game? No, so this likely won't either

It's unfortunate that such a benign topic can so quickly degenerate into partisan bickering. Keep it clean, every one. I don't want to see any personal insults or posts that drag the thread off topic.

Sonic Boom 3DS/Wii U are in no way, shape or form the same game.

Neither are Smash Bros 3DS/Wii U

Based on what ur saying, Mario Kart 7 and Mario Kart 8 should be cross-buy.

Cross-buy only works when the games are the same, none of the examples u have used are the same game. Smash Bros 3DS is not a scaled down version Smash Bros Wii U, they are two seperate games that were built from the ground up using the respective hardware.

What's different between Smash Bros 3DS and WiiU?

The fact that they are both built from the ground up on different pieces of hardware makes them, by definition, different games. They aren't simply ports of one another.

Yes but not in the way people think IMO.

Lets take a standard game like Super Mario Galaxy 3. All games ship on 3DS/Vita sized cartridges, which can range in size, 4GB-32GB by next gen (most Wii U games are under 16GB).

Mario Galaxy 3 - Console Edition $59.99

Mario Galaxy 3 - Portable Edition $39.99

They're the same game, except the portable version runs at 960x540 resolution lets say, and the home version runs at full 1080p with a few extra graphical flourishes. If you buy the more expensive console edition, it's $59.99 it works on both the home and portable Fusion right out of the box.

If you buy the portable only version it only works on the handheld version *but* you can always go into the eShop, pay an extra $20, and "upgrade" to the console version at any time and voila, now you have the console version and can play on the home Fusion too (for TV play). Lets say you buy the home Fusion model 8-9 months later and you want to be able to play your copy of Galaxy 3 on your TV in 1080p ... well just go into the eShop and pay the extra $10-$20.

Kinda similar to Nintendo's policy for Wii VC - to Wii U VC transfers, if you owned say Super Mario World for the Wii (VC), to get the version on Wii U didn't require you to rebuy the game, but you did have to pay an extra fee, that was like 1/3 the price to get the Wii U version which had gamepad play.

Wrong topic.

The theoretical "Fusion" need not apply. Wii U has NES Virtual Console games. 3DS has the very same NES Virtual Console games. I don't care about Smash Bros, if they want to sell me a full-priced game twice they're welcome to try. But they should make it so that I only have to buy a NES game once to play it on any of their platforms. Basically, Virtual Console should be just that: a console. A digital platform. Not a catalogue.

Smaller titles like Mario & Donkey Kong series and VC and stuff like that, yes cause they will be the same version on both platforms but bigger titles that are exclusive to the said platform like MK9 and MK10 will be a no cause they will offer experiences different enough to justify the cost

The idea behind Fusion is that one game is playable on both consoles,without paying extra.

This strategy doesn't lose money on software, on the contrary, every game has by default a bigger audience to sell to.
What might make Nintendo lose revenue/profit is HW sales as people bua lty both consoles to play all Nintendo games. Yet, that might not happen because the Fusion strategy, coupled with a rich and diverse line-up might just attract a lot of people who normally don't buy Nintendo products, for one reason or another.
Sony and MS fans, who don't care for the portable experience and who find the HC lacking in quantity and diversity, will probably be attracted if they are offered 2 consoles for the price of one and their type of games (all exclusive to Nintendo consoles).