Google Caffeine (being tested at: http://www2.sandbox.google.com/) is different than the current Google.
When you visit the Google Caffeine test page now, you see the following message:
"We appreciate all the feedback from people who searched on our Caffeine sandbox.
Based on the success we've seen, we believe Caffeine is ready for a larger audience. Soon we will activate Caffeine more widely, beginning with one data center. This sandbox is no longer necessary and has been retired, but we appreciate the testing and positive input that webmasters and publishers have given."
So, the time has come. Caffeine is being rolled, data center by data center.
http://searchengineland.com/caffeine-googles-new-search-index-23823
Making sure you continue to rank well in the new Google is important. Do not think that just because you rank well in the current Google, you will continue to do so in Caffeine. This does not mean that you should panic though - if you are and continue to follow best practices and are actively optimizing your site, you should still show well in the serps OK.
A few things to keep in mind:
Real time search is becoming more and more important, so make sure you are Blogging and using social networking media. Also try and make sure you carry on trying to get into Google News with regular news updates on your industry.
One of the major changes to the way sites are ranked will be "The load time" of your site. Google is looking for speed:
"Historically, we haven't had to use it [load time] in our search rankings, but a lot of people within Google think that the web should be fast," says Matt Cutts of Google. "It should be a good experience, and so it's sort of fair to say that if you're a fast site, maybe you should get a little bit of a bonus. If you really have an awfully slow site, then maybe users don't want that as much."
So that means that your Hosting and Host starts to matter. If you are on a server that dsoes not respond within acceptable limits you could be penalised by Google Caffeine.
With fluctuations in rankings and people dropping out of the index as Caffeine rolls out, it's the perfect time to get your site optimized and get going on social media and Blogging so you can jump in and take some of those top rankings.