It will do the exact same thing that every google update does:

• Make search results more relevant
  Remove crappy sites from the top ranks
  Improve user experience for searchers

There's no surprise when google has an update. Crap sites that dont belong at the top of the search engines are removed, and they are replaced with sites that have better content and are more relevant to the search term.

Yeah, but more specifically, what type of sites do you think will get hit?

Obviously, we can't really tell what specific sites will be shaken by Google updates. From the previous Google updates, article directories took a lot of hurting. A reason why most of them changed the guidelines for article submission.

I think Google is moving towards personalized searching.

No one can say for sure what the Google guys will do, we can only say after we experience its update. But somehow every update does the same thing like improving search results and getting relevant content to the users.