It's weird for me this is my first halving as an active participant. I made my mind up on what I am expecting, it's an incredibly narrow look at things overall. Thinking about these things is why I have decided to get myself to capacity sooner rather than later for my personal mining. This way by the halving my machines won't owe me anything
I expect the block reward to be cut in half. I know very bold statement but I think I can stick by that. 
Seriously though,
I think pricewise is is going to look like September to December 2017, before the halving. Not necessarily the same ATH, but maybe around 13 000$.
I believe we will see a large increase in hashrate leading up to the halving, from people throwing not necessarily profitable machines online to earn as many coins as possible. They will be banking on a price spike after the halving.
Immediately after the halving we are likely to see a pretty good drop in hashrate; more than the increase leading into it. I think that many people are going to become non-profitable shortly after the halving. Unless there is a large sustained rise in price to offset the lower mining rewards.
My biggest hope, is that with the block reward cut. Certain pools will stop mining empty blocks, or their miners realize how stupid it is to mine at these pools.
Haha, i was thinking 'yes, first guy on the hook to share thoughts' and then... (in bold)... I was thinking just about this is all i can predict too!
I hear a lot of confidence about the price going up, i) its happened before previously ii) the coin supply halves therefore we need to have people selling only at double their previous biting point in production... but... why? Why can't it just be they go out of business at that point? Why can't leading up to it can it not lead to depression of confidence as miners know they need to halve their production costs or have the price double..
Surely confidence is down and I see the halvening as mysterious and an amplifier of whatever sentiment there is at the time, i am typically skeptical person (read: pessimist?) but I can't see how with limited change in utility [tick!], limited change in adoption [tick!], and overall negative/bearish sentiment [tick!] how the fact that half as many coins will be issued can be a good thing, I would like to be shown both here in arguments and later in reality that I was wrong

My overall feeling is: its a shock and its curious and so it will just double down on whatever the market sentiment is overall.