Haven't read everyone's response so may I repeat someone's points earlier. Anyway:
Pros: More software on one device besides less software for two devices
Cons: Software like Mario Kart and New Super Mario Bros. gain a lot of sales for releasing in two different types of consoles. Unless Nintendo release more than one Mario Kart/New Super Mario Bros. per that generation, Nintendo needs to make sure those games sell as much as two versions.
Pros: Some games may be cheaper because most software should be able to run on the handheld version.
Cons: Pricing on games. How will Nintendo decide how much will a game cost? Do all games cost 60$ because they can run in a higher resolution on the home console model or will all games cost like a handheld game ($40) because most can be played on those?
Cons: Marketing their games: How will Nintendo market games that are made for handheld in mind? And will the consumer and gamers see games marketed and priced like handheld as lower budget titles? This is a possible concern now because all titles should be compatible in all Nintendo fusion models. Smart device games don't suffer from this because they have very few games that take advantage of the tablet screen resolution or specs.
Pros: Nintendo is less likely to be stuck with a home console with lows sales. Currently the Wii U and 3DS have different specs but the fusion model should have the two with very similar ones. If the home console version has low sales, they can still produce titles on it because consumers can buy and play them on the more successful handheld version.
Cons: Fusion represents a going all in mentality. If the fusion model OS or core specs doesn't resonate well with the market, all version can face disastrous sales and Nintendo won't have another handheld gaming device to back them up.
