Everyone seems to be forgetting that the NX could still just be a dedicated home console. To date, we still only have rumors to go off of.

And in both cases of the 3DS and WiiU - the new platform struggled out the gate. 3DS of course hit the brink, but then did OK. WiiU couldn't recover. I think Nintendo realizes leaving legacy platforms totally behind can be risky in today's market.

Nah it makes sense because NX is not 3DS-2. 

It will be more expensive and a lot bigger than a 3DS/DS/GBA/GB lineage so keeping the 3DS around for a couple more years as the cheap/small option makes sense. 

They struggled because they had no games (and well high price, poor marketing, etc.), not because their predecessors didn't continue getting support after they launched. Making 3DS games means less NX games, which goes against what you'd think should be their strategy of actually having games and no droughts for the NX. Nintendo can only make so many games whereas Sony and Microsoft have 3rd partys they can rely on.

Yes, I know Nintendo will support 3DS even in 2017 regardless NX, but this is very strong support, like it middle of life cycle for 3DS not end, it seems that NX will actually be more home console than handheld.

3DS = 100% BC (cart + digital)

WiiU = ~partial BC (digital)

That is my prediction.

In 2013, the PS3 got Sly Cooper: Thieves in Time, The Last of Us, God of War: Ascension, Ratchet & Clank: Into the Nexus and Gran Turismo 6. Was the PS3 dead in 2013? No. But its successor still launched the same year, because it doesn't pay off to wait til your systems have died down completely before you launch the next.

Digital 3ds is possible, I expect zero compatibiility with WiiU and no cart slot for 3ds games. The rumours surrounding the NX suggest that it won't be powerful enough to emulate WiiU games given it's different architecture, and they're not going to include WiiU hardware for the purpose of BC.

If I have to make a prediction however it would be no backwards compability at all.

Actually It's not hard to imagine they worked on 2D Pikmin for 3DS and full 3D for NX.

Not just on rumours, but more based on Nintendo statements also, and their actions.

Actually Nintendo usually abandoning their platforms one year before new arrives, especially home consoles. 3DS having very strong support in 2017 is pretty unexpected.

To be fair all this 3DS titles are not big projevts (expect Pokemon), there is quite good numbers of ports and spin offs, and that points that all big teams are working on NX games, not to mention that last bigger Wii U game that isnt small project, port or spinoff is announced at E3 2014.

Yes, exactly. Add to that Nintendo need a way of making money if NX bombs out of the gate, which is entirely possible. By this point, 3DS development is cheap and the user-base is large, so this is a good way for Nintendo to strengthen their bottom line. Until NX and mobile take off--and for all the success of Pokemon Go, those factors are far from certain--3DS remains Nintendo's primary revenue driver. It wouldn't make sense to drop that like a hot rock. Wii U support has stopped because the system is a commercial failure and it's not viable for Nintendo to support it.

Another point I'd make is that some of these titles--like the two Dragon Quest games--came out years ago in Japan. Localisations and ports aren't exactly resource intensive endeavours on Nintendo's part, so I wouldn't be surprised if 3DS rounds out its life in the West with localisations of stuff like Detective Pikachu, Lady Layton and Monster Hunter Stories, and perhaps even ports of things like Tropical Freeze and Captain Toad.

Finally, if NX does have a strong portable element and uses 3DS style cartidges, it may yet be backwards compatible with 3DS. It'd lack stereoscopic 3D, but 3DS games look great in HD as you can seen from the recent emulator knocking about online. I wouldn't rule anything out at this point.