im seeing multi subdomains in the top 10 all over the place.
Sites formerly at no. 9 and 10 are now no. 1 and 2, and vice versa!
I've had one site online since 1997 that had a lock on the top spot for my keywords on and off for four years on Google just go "poof",
Most of my competitors have been hit the same and my SERPs are generally an irrelevant mess of shopping sites or single pages with absolutely no information on them apart from maybe an image and a couple of keywords...mess, a total mess.