TheMadScientist - 6:15 pm on Jan 10, 2013 (gmt 0)
They have to get the list, spider the pages the links are on, then run Penguin again ... It's not anything like an 'overnight' fix.
There's a thread with a longer more detailed quote containing the info from John Mu here somewhere, but I'm not sure where off the top of my head ... The above is 'the short version' of what I remember being quoted from him by someone here.