It probably has an impact, but to be honest that's just speculation. Google (let's face it, that's the one we all care about) keeps the details of its algorithms to itself, so while there are lots of guesses about how search rankings are impacted by bounce rates, the truth is that no one that doesn't work at Google really knows.
The thing is that certain types of websites naturally have higher bounce rates than others. A webzine likely has a low bounce rate, because people click on articles from the landing page and stay on the site. Amazon has a low bounce rate because people often look at lots of stuff while shopping. A blog probably has a high bounce rate because the blog post that people want to read is on the landing page, and many readers leave the site after reading the latest article/post. I think it is unlikely that Google would ignore these differences and treat the bounce rate as a determinative factor for search rankings, although it probably does "move the needle" slightly.