When you are editing an existing blog entry, the line feeds at the end of a line get lost.  You can initially post it, but once you go edit it, you loose them all. 

This is mainly when you are using <pre> tags and <textbox> tags when this functionality is important to persist line endings correctly

Is this a bug?  Create a blog post with <pre> data with normal returns, save it, and then go edit it and you will see they are lost in the conversion somehow.