No, for me it's Google's Panda update for sure. In my traffic stats on Google Analytics, traffic took a nosedive of 50% precisely on February 24, when Google rolled out the Panda update.
If you think you have done the right thing in optimizing your site, we can say that the recent Google update is the reason why your rankings dropped.
This is the reason why I gave up on relying on Google for traffic. I am getting better highly targeted traffic through article marketing, forum marketing, Twitter, and Facebook.
No, it is not just a "dance". It is the Panda update. Exactly on Feb. 24 my Google traffic dropped 50%. So did the traffic of many others, precisely on Feb. 24 when Panda was implemented.
the first thing that I would say is keep doing what you did to get it there. google will always be changing the algorithm for its indexing. but one thing will not change, relevancy. keep it relevant and google will like you