I seriously doubt that a lot of sites are going to be de-indexed. I expect that a lot inner pages for certain sites might change their positions in the results pages. If this happens, website owners are just going to have to figure out what happened, and make some changes.

For my most targeted keywords, all of the typical sites are still in their places, and my sites have not dropped or gained any positions.

There are a ton of sites/rankings to check, but went through all the important ones and so far so good. All of our rankings seem to be the same. Some rankings have improved, although those were rankings that were already on their way up.

The site I'm trying to sell dropped this morning from a PR4 to a PR2.

Bummer.

I wonder what SEO will still be relavant

Same all around