Q: Ipod Nano no longer recognized after latest update to itunes!

Same problem and both heartened and disheartened to see that others with this problem have not been given a satisfactory answer.  I thought it might be my Ipod at fault but found I could sync on an old computer with previous versions of Itunes.  That tells me that the problem is Itunes and Apple needs to fix it.  I will try the repair idea but I doubt it will work.

I'll echo my iPod Nano 5 (blue!) will not sync.  iTunes recognizes its an ipod, makes zero effort to sync, disconnects it and I can't even get into it from windows.   I even went and dug out another charger cord.  I am confident, based on the fact others are saying it, it is in fact iTunes.  Please fix it Apple!  I just downloaded new songs!  

Still not a fix here.  Has anyone been able to get their sync to finally work? 

Resetting the iPod by holding "Menu" and the centre of the wheel for 15sec while connected and then restoring the iPod from iTunes was a good first step.   Then, dismounting & unplugging the iPod, shutting down iTunes and restarting the MacBook did the trick.  Once OS X rebooted, I plugged-in the iPod and it mounted, and I'm able to sync my iPod from scratch (which is what I was after anyway).

If you're hoping to save the music you have on your iPod that you don't have in your iTunes, then backup before doing this.

I hope this works for you.
Best,
David

MacBook Pro (13-inch mid-2012) running OS X Yosemite 10.10.5
iPod Nano (2nd Gen 4GB) currently (after the above) running 1.1.3

So none of the solutions posted worked for me.  Having said that, thankfully we have received a new iTunes update today and my iPod now syncs!  Huzzah! 

I'm glad someone got an update that worked for me.  Mine still is not working!

Correction:

* I'm glad someone got an update that worked for them.  Mine still is not working!

I hope by now you've found a resolution to this. I keep my iPod attached to my car and just brought it in to sync it for the first time in 6+ months and ran into this problem. I'm running on an iMac with El Capitan so it may not be the same environment. However, what worked for me is plugging my iPod in, going to Disk Utility and "Unmounting" the iPod. I then went to iTunes and did a Restore and it worked perfectly. Hope that helps!