Will the 3DS sell better in 2016 than in 2015?

[PAOerfulone]

No.
Yes, next year's lineup is looking very impressive.
In fact, I'll go as far as to say 2016 is looking like the most impressive lineup for the 3DS since 2013, which was the peak year of the system. In fact if you look at the 2013 lineup and compare it to 2016, there are lots of similarities.

2013: Fire Emblem Awakening 2016: Fire Emblem: Fates
2013: Shin Megami Tensei IV 2016: Shin Megami Tensei IV: Final
2013: Mario & Luigi: Dream Team 2016: Mario & Luigi: Paper Jam
2013: Youkai Watch 2016: Youkai Watch 3

Plus other titles like Bravely Second, Pokemon Z, Federation Force, etc. If we're lucky, we'll get Gen 7 of Pokemon in celebration of the 20th Anniversary. If all this holds through, then 2016 can be just as impressive if not an even more impressive lineup than 2013, and software sales will definitely be up, YoY compared to the past 2 years.
But, that's only for software.
Hardware sales, I expect to be quite down. In fact, next year, I believe will be the weakest, lowest selling year that the 3DS has ever had for 2 reasons.
1) The reason why I brought up the similarities between 2013 and 2016, is because during 2013, it was obvious that the 3DS still hadn't reached its peak and that the software lineup they had that year would bring about that peak year, and highest point in hardware sales. With that said, the people who bought a 3DS, any 3DS system, that year for those games, will already have one so that they can buy the next installments of those franchises next year. The target audience is already there, plus potentially new fans and sales, due to the increase in install base that has added these past 2 years. And if there is a spike in sales for every time hose games come out, they won't be as high as they were back in 2013, because a majority, if not the entire audience that wanted to buy a 3DS system to play those games, has done so already.

2) The 3DS has been holding steady in hardware sales units these past 2 years, despite the software lineups not being anywhere near as impressive as they were during 2012, 2013, or 2016 for that matter. ANd the eason for that is simple. Q4 2014 - New 3DS came out in Japan, HUGE spike in sales. Q1 2015, New 3DS came out everywhere else in the world, another HUGE spike in sales. And for those reasons alone, 2015 and 2014 are looking very even in the hardware sales department.
Unless there's a New 3DS 2 in the works, there won't be a new, refurbished system coming out in 2016 to experience that HUGE spike again. And that with the established audience that already bought the system for back in 2012 and 2013 for all those franchises I just mentioned, and will already have a system to play the next installments.
I'd expect a pretty steep drop in 3DS sales next year.