It seems to be mainly the sites that were affected in the mid-December algo change that are seeing changes on these datacenters. If you didn't see any changes in your area in mid-December, you may not see anything unusual on these datacenters today. If you were badly affected by the mid-December blip, then you may see positive results on these datacenters today. (my observation only)
Yes I agree. My site took a small hit in September then a massive drop in December. It's a regional travel site that had been performing very well for years in Google. In December Google referals went from 25,000 down to around 1,000 per day. Yes I was freaked! The site is clean and I did nothing SEO wise in Sept. or Dec. I simply continued to add content, get links (over 1,000 now) and worked on a new site as well. Today wella...back in the serps in a major way.
What we're seeing is not a daily flux (listen to dazzlindonna). For those of us destroyed in the December 'limited update' this is significant - I have one site that went from 8,000 Google referrals a day to 400 - this has returned to #1 on many phrases. I also have other sites where I can see no discernable change in rankings. So, another limited update - whether you attribute this to glitch or filter is up to you. If your sites weren't hit in December you will barely notice this.
I agree with Iguana...I shared this exact experience.
After 5 years of consistent, good, search results ranking, my site as almost disappeared - not even first when search on my company name. This is absurd..
sailorjwd - Assuming your doing good SEO I would recommend working on a new site, work on getting backlinks or start a new hobby for a few months. Because you will drive yourself crazy otherwise, I know from personal experience.