I've been searching for a answer to this since before the Panda update (namely, how are subdomains viewed by Google's algo).
3 years ago, I heard talk that subdomains were treated as separate websites, and as such one would conduct SEO as if they were separate.
With more and more big players using subdomains, it seems as if they can be implemented without being seen as separate sites.
In a post-Panda world, do sub-domains reflect on the overall quality score of a site? Or do they each receive their own quality score?
I understand this may be difficult to determine with any certainty, but I'd be interested in hearing the experiences of others with regard to this issue.