Google Panda is coming 24 fab 2011 have some major updates but right not is applicable only at US & UK based website but after some time latter at worlds wides.
the main concept of Google Panda is given first pages position for those websites having more and more information and services based content, if website having low quality as per user and also search engine point of view then don't offers better search engine ranking.
if your website position are going to down then your user behavior must be down
Its not after Google panda, Actually whenever you will submit a fresh and original content to your site then definitely it will give some kind of benefits in this regard. Panda has only increased the need to submit the original contents at all.
According to Google Panda it will filter those website having duplicate content & trying to spam other websites. Hence, it will produce great result in SERPs by declined those websites. And well if your website has good content & services then traffic will automatically increase toward your site.
Actually, I have read that there are website owners who experienced a PR increase since Google announced the recent Google Panda update. The truth is, Google Panda update focuses on trimming down websites with duplicate and low-quality content, specifically content farms such as Ezinearticles, Buzzle, etc. Thus, if you think you're not affected by that update, then you can assume that you're pleasing Google with your strategy.