inventfilm

When importing your blog from blogger you may cause your posts to reappear as duplicates in your subscribers feed readers, unless you install this plugin and set the “Not Before” date to the day you switch.
This plugin works best if you have already been using feedburner to “burn” your feeds in blogger.
<h4>Why would I use this plugin?</h4>
If you are using blogger and feedburner, then after you import your posts into wordpress and change your feedburner “Original Feed”, your subscribers will see all your old posts reappear in their news readers as new unread posts. This plugin allows you to remove all those “old posts” from the rss feed which, after switched the feedburner feed source, will make the blogger to wordpress transition completely seamless.

RSS Not Before

RSS Not Before provides the ability to remove posts from the rss feeds prior to a given date.

Stephanie Leary

Allows you to import only selected content from WordPress, Blogger, or Tumblr sites. From the Pending Imports queue, you can select which posts to import, and which content type they should become (posts, pages, or any custom post type).
Sponsored by <a href="http://pressbooks.com/about/" rel="nofollow ugc">PressBooks</a>.

Selective Importers

Importers that put the incoming content into a queue, where you can select which posts to import.

RSS Not Before vs Selective Importers