I suspect that the halving will be priced in progressively as the time approaches, since we've all seen a halving already, so probably less lag this time. Along with that I expect a price increase as we get nearer to the event, but nothing dramatic. Lastly I would expect to see a hash rate drop of similar proportions, and life will go on...
There are much more interesting events on the horizon than halving.
In bitcoinland?
I'm not sure about that. If the price doesn't increase that means the difficulty/hashrate have to halve as well. Meaning the entire network becomes 50% weaker. Against any attacker.
Bitcoin needs value not just to be able to transact significant amounts of money, also to secure the network properly.