Marketing_Guy - 3:28 pm on May 16, 2012 (gmt 0)
Paid directories don't seem to be hit as hard - I've a list of 100 or so that I've been keeping an eye on and only 3 have been blitzed (completely de-indexed, but still have TBPR...).
The common issue between them was allowing keyword laden anchor text (which is common in free directories too). Makes sense they'd be on the hit list tbh.
There has to be only maybe 2k-5k free directories out there that are being used regularly (submission services, etc). Realistically if Google is slapping people with exact match anchor text in Penguin, you could also use that data to identify common sources of exact match links. Given directories are mass-submission techniques, it makes sense that they'd appear at the top of the list and are likely to be the first place Google kills off.
IMO just the start. If Google is using backlink data to identify the common source of spam, it's only a matter of time before they can refine the process to indentify more subtle offenders like smaller content networks and so on.