crobb305 - 2:48 pm on May 31, 2012 (gmt 0)
I had two sitewides removed around April 30th, only about 50% of each set have been removed in WMT or the visible cache in the serps (on site: search). Google is very slow at spidering the web, so I'd say a couple of months at this rate. It definitely makes me wonder how WPMU.org's recovery [seomoz.org] happened so fast...all of their backlink removals seemed to be "counted" immediately. I had some backlinks removed in the same rapid timeframe, and they are still being counted by G.