No, there isn't any simple way to classify sites... At best, you can find common signatures and try to classify them by that. For example, looking at WordPress in particular, it appears to be one of the few that returns the "X-Pingback" HTTP response header.
SELECT count(url) FROM [httparchive:runs.latest_requests]
WHERE firstReq = true AND respOtherHeaders contains 'X-Pingback'
Above query matches 6779 sites. From there, you can extract the urls and analyze them by rank, perform reverse IP lookups to figure who the provider is.