I'm missing this feature so much as well!
It's been amazing, when turning quick notes to a small presentation for a client or business partner. @PinkElephant Although I agree, that not all users will be using the feature, I feel that it's an easy "step up" feature to pay a premium price as presentation mode is something that earning adults and knowledge workers will use the most.
I really hope to see it come back. Losing this feature made me turn away from evernote for a couple of months.
It hurt so much to see it go.
Best