gyppo - 5:45 am on Dec 30, 2011 (gmt 0)
Not long tail, short tail queries + long tail.
90% Panda fall since Feb, 20% recovery in the last update. We've taken the site from 150k indexed pages to just 450 in the last month (to try & shake Panda once & for all) however the terms I monitor include just the 450 pages (everything else is pretty much deindexed now). I'd also say the quality on our site has increased drastically compared to people competing on the same SERPS.
Could just be normal Google flux & the terms could bounce back in a few days, I've seen it happen before. But I posted just incase anyone else was seeing anything similar.