Fabrice Canel from Microsoft Bing said on Twitter “preferable to use a 302 redirect if your destination URL may change within 2 days, else 301 is recommended.” So if your redirects will be in place for less than two days, go with a 302 – otherwise, Bing recommends a 301 redirect.

Here is the tweet:

301 redirects are by definition permanent redirects and 302 redirects are temporary redirects.

Update: More from Frederic:

Forum discussion at Twitter.