Add my vote and voice to the growing number of people disappointed by this news. As a user of OneNote every day, this is very discouraging. Spinning this as a positive angle is very misleading, but sadly not surprising. Why would anyone be excited about what you just announced?
I championed OneNote for so many years, as I constantly defended it against the Evernote legion. Somehow it is still, in my opinion, THE application that many Office users don't even know about or what to do with it - it is drastically underrated and underestimated in its current state. You could maintain, and improve on the quality product you have right now, and market it effectively to let people know just how good it is and what they could use it for in their situations (I still have friends and family pasting text and pictures in Word for various notes they want to keep for future reference - wow!)... but instead, you've chosen to kill off this great product and replace it with an inferior substitute and try to convince people that they are wrong for wanting "local" functionality. Sure, the cloud is all the rage - fine go in that direction, but leave some ability to store on local storage (and no, saving to OneDrive is not the same thing) - why force it?
The good news about this announcement for me, which is quite far in advance luckily... it will enable me to start looking around for alternatives now. I will stop using OneNote as Microsoft's intentions are very clear, and stop wasting time using a product that has no future in my lineup of tools that I use. I'll keep an eye on this "new and improved" OneNote, but unless its development takes a drastic turn back to rationality, I will sadly be actively looking for a replacement.