If I were you OP, I would not expect much from ETFs since they won't impact the market that much because:
I'd like to say the same thing as well that don't expect too much with it but understand what really ETF's are. It will determine a small price pump but just like what others said that you have to know the details regarding it. Just like what's with bitcoin futures before, a lot of people doesn't have an idea about and is only thinking about the spikes. I also agree with those that said it will create a short term pump and later on we'll be back on where it used to be. Well, I don't know if SEC is playing with this they keep on delaying it.
I am not really expecting anything too much from the whole ETF approval anyway, both in terms of it getting approved or the impact it would have on the price. The market will behave however it wants to behave with or without the ETF and even though we expect that in the long run, this would bring in more smart moneys into the system, but at the same time, we would not just expect some skyrocketing over night because of that.
Simply, we might experience a short term pump as a result of speculation, but that still does not change anything as a lot of people would expect, but surely, it would bring about a matured market in the long run.