What is going on with Google

Sounds to me like what is going on with Google is the same thing that has always been going on with Google.

 

Yes, thing have changed pretty much from last few months, especially after implementation of Google Caffeine.

Change in SEPR, is depending on that how fresh your website content is! if you had fresh content every now and then then then for sure your site will get a good number of hits from search engine, oh.. yes, backlinks do play a role in it, your PageRank should be high enough for getting in top. I personally observe, this thing, since i use to maintain a tech blog and when ever i use to update it traffic increases significantly and as that post get older traffic volume from search engine start dropping.

If you want constant traffic on website, then you must maintain a good PageRank, and continue your off-page campaigning.

 

Yes Due to Google dance!!

 

there is some research going on i suppose or could be some testing of pre-release google SERP algorithm.

 

Yes I also noticed that Google fluctuating on some keywords.