Even if they are working on that (which I think they almost certainly are right now) they won't show that until next year. Showing a new handheld now and then not releasing it for a year would just skewer 3DS sales for no reason. 

They always unveil their hardware 1year -2 years before the actual release. They unveiled the wiiU in 2011 and the system released in 2012. Same thing with 3ds (altough it was a early 2011 release but still).

They unveil their handhelds generally pretty close to launch. 

DS was unveiled in 2004 and launched in 2004. 

3DS was unveiled in 2010 was supposed to launch for late 2010, but they didn't have enough games ready. 

They can save the new handheld reveal for next E3, there's little to no incentive to show it this June. Nintendo needs to squeeze as much profit out of the 3DS for the next fiscal year, because Wii U sure as hell is not pulling its weight. 

Reggie jokes
fall / winter release schedule (2-4 new games)
some hardware push / bundles (wiiu/3ds)
new hardware (not wiiu) / 3DS related / more info on QoL

Sounds like you are just dying to be disappointed. 

I expect a sequel to Nintendo Land and an extra long showcase on the new and improved fireworks that Miyamoto has been hard at work with. Retro will announce that their next title(s) will be DLC for Nintendo Land: Mario and Friends.

I love how everyone just assumes they will drop their current systems prematurely. 

By november 2015, the 3ds will be almost 5 years old. That's not exactly what I would call "dropping their systems prematurely". Especially when you look at the usual life cycle of Nintendo products.

Perhaps that you're right, but a holiday 2015 release for their next handheld is pretty much set in stone at this point seeing the continuous decline in sales of 3ds hardware.

Going for the non-obvious things: CoD Vita ported to Wii U with Ghosts engine!