they make adjustments to the algo, in Matt Cutt's words "approximately 3-400 times per year" every day, or near enough
he might be lying. as far as from my experience, google slowly change their algorithm. Same oldie techniques always work until today.
I can see quite good movement of SERPs since last 2 days. Might be due to internal backlinks or PR update. Might also be due to other changes. But something has been going on most recently.
I don't know exactly about Algo, changes in Google, but ya i am quite sure about Page RAnk, it's going to update very soon, so check your websites...
I think the update is coming soon. Maybe on 31st March like 31st Dec. I see the whole DC set of 216.239.51.XX as OFF.
i don't think they will publicize their algorithms that soon, you have to know it for yourself and that's one of their schemes perhaps.
What i am asking not PR updation and SERP's changes on google, when the last updation of google algorithm?