Nintendo seems like it has built a decent lineup for Switch through the end of July. There will likely be a big shipment of Switch around MK8D both of which should sell well and consistently throughout the system's lifespan. Minecraft won't be a system seller but should be a good evergreen title selling consistently over the years will over time sell over a million copies if not more. USF2 may do ~50k LTD but who knows for sure. Another big Switch shipment will hit mid-June with ARMS which I think will be pretty big in Japan. Then in July another big shipment with Splatoon 2's release. As I stated before, I expect Splatoon 2 to be like Melee as the original is to SSB64. I expect Splatoon Mania to be much bigger this time around. Then there is Fate/Extella which will likely sell ~70k, which is roughly in line with what the vita and PS4 versions launched at.
I'm curious what Nintendo has to keep the momentum going after July. I expect to hear more news about that at E3. I could see Skyrim Remastered in August which could sell 25-50k, which would be in line with how it sold on PS4 LTD over the holidays. Fire Emblem Warriors and DQXI could be September releases. I'm still inclined to believe the Stars rumor and I could see it launching in October. While GF usually waits 2 years after a system releases and then releases a brand new generation. They've been breaking away from a lot of traditions in recent years. I could see them releasing the Pokémon sun/moon 3rd version on Switch. The engine, overworld and models are already built to rather easily scale the game to HD. Have a remixed version of the Sun/Moon content with an added post-game to travel to Kanto and face the gym leaders/E4 with some more Alola Forms and Mega evolutions added in. That would be more than enough incentive to get Pokémon fans on board for the Switch. Then Odyssey in November and Xenoblade 2 in December. I also suspect there may be some surprise 3rd party games releasing in the fall 2017 time frame but likely just 3DS/PS4 ports like MH XX or something.
As for 2018, Nintendo has said that their 2018 lineup will be bigger than their 2017 lineup which is exciting. I could see Smash Bros releasing in February 2018. I can't see Smash Bros. releasing in 2017 given everything else releasing. Sakurai has been quietly working on this for a little while and knowing him he is adding new characters, stages, fleshing out different modes/options, including new modes
etc. Fire Emblem Switch/3DS will likely be an early release like March. Retro Studio's game, coukd be their big May title. Then there is still other franchises such as Mario Party, Pokken, Super Mario Maker, 2D Zelda and Animal Crossing that could make 2018.