I've seen websites with 70+ bounce rate with no Panda penalty. Your bounce rate from Analytics is no important. The one from Google search engine itself is important and probably used.
It depends on the site and niche. I would aim to keep it under 50% for the site average unless your site is very small. Then high bounce rates ares expected. What google looks at are bounce rates from searches. If a user clicks on a link from google, lands on your site and then returns to google immediately. These visitors are telling google the search term i used is not relevant to the landing page. If you have a high bounce rate with low time on site, your serps will be affected.
With panda updates, I've learnt to keep good contents, regular feed of sites, and hence I achieved in getting good PR pages this time. Last time, even I was broken.
You all have share a nice information.i have gain a good knowledge.Please keep sharing more and in future. Thanks
Below 40% is fair enough for Google. If you have bounce rate more than 40% then you should work on it otherwise nothing to worry about.