I think we need to stop saying 'wait and see' and getting people's hopes up. The longer you wait for this to be reversed/your rankings to come back the longer you're not putting effort into building a new site and/or putting effort into your other sites.
I've seen a steadying of rankings over the last few days (health niche). I cannot see any major changes occurring over the next 48 hours. If you've taken a huge hit then take it on the chin and crack on with other sites. Waiting and hoping everything will be ok is the worst thing you can do. Yes, this update is absolutely terrible and some of the utter (sometimes irrelevant and spammy) trash that is ranking is a joke, but we have zero control over it.
I am experimenting on one page with H tags, meta description, keyword density and the like, so I will post up any findings to see if this is something that could be rectified through alterations to these.