I've noticed it. I just didn't care all that much.

Lack of new content to drive buzz and sales.

E3 will likely fix that as I think Nintendo has been focused on WiiU, but 3DS will get some notable information soon. Plus as SSB releases it will rebound.

I have already a big 3DS backlog as I mostly use my Wii U these days.
I do not consider it a good handheld. It is far to difficult to use in sunlit areas as it is hard to see the screen. I mostly use it in bed at night and now the Wii U gamepad can serve that purpose. The Wii U does lack some of the games that does the 3DS attractive.

I had noticed too. I think it is temporary if they can just keep good games coming. If they can't, then 3DS may continue downhill. Nintendo needs to speed up their game making process.

I haven't turned on my 3DS this year

The DS in its third, fourth and fifth years sold almost 2 million regular months and more than 7 in december.
http://www.vgchartz.com/tools/hw_yoy.php?reg=Global&start_year=2004&end_year=2014&console=DS

The 3DS in its fourth year struggles to reach half million in regular months.
http://www.vgchartz.com/tools/hw_yoy.php?reg=Global&start_year=2011&end_year=2014&console=3DS

No games, all the big releases lately have been on consoles, as has the focus on E3 for consoles as well. 3DS will chug along until SSB releases in August, then it will stay strong until the holiday season.

Frankly, I think it's time is coming. There's just not much of a market left for it.

2004-2006 Nintendo ds 19.000.000 2006-2009 Nintendo ds lite 94.000.000 2009-2011 dsi/xl 41.000.000 2011-2014 3ds/xl 43.000.000 an probably 55.000.000 or more until the end of 14  , actually 3ds falling short in ds lite...we have to compare 3ds with each handheld individually:P actually did you claim the same things for dsi ,94000000 to 41000000?2014 is the third year for the same console ,so falling is expected, but smas bros is coming and of course ruby sapphire remakes will surge 3ds...this title is much in request and could retrieve people who stopped playing pokemon since hoen...!we have to wait seven years to compare 3ds and ds as series:P

There are no longer any simple solutions. At this stage in the game, it's too late to introduce an appreciable number of new 3DS titles which are not already in the works: since development time has increased along with development costs, you'd be looking at late 2015 for any traditional attention-grabbing title which started development today. That would put the system in fifth-year territory, and while it's not unheard of for a system to enjoy a renaissance at that stage (see: Boy, Game) it's not something I would bet the farm on.

With that in mind, I would propose the following rough ideas for the short-term: create multiple new small development teams, some as small as ten people, and challenge them to produce completed software within the next 9-12 months, presentable prototype ready within six months. At that mark, evaluate each team's progress, cull the ones that are obvious stinkers, and shift resources to the promising ones. I expect most to be duds, of course, but having a few of them be hits will do the system an immense service.

This isn't a novel idea: it's what Nintendo did last generation with the DS, and the results were games like Brain Training, Art Academy, 100 Classic Books, Big Brain Academy, Flash Focus, and the Personal Trainer games. These games not only brought in tidy individual profits, they also expanded the appeal of the system to folks who normally would never have bothered.