A new setting has been added to the profile settings: Automatically detect and convert plain text. This setting is turned off by default, but when turned on will convert existing plain text fields to HTML so paragraphs and line breaks are preserved. This only occurs when editing the node for the first time with FCKeditor. See #575626: Activating Fckeditor breaks existing node formatting for more details.
#724584: Three small typos in the file 'fckeditor.config.js'
#716274: Clone Profile incompatible with PCRE <7.0
#701736: warning after update from fck-editor 6.x-1.4 to fck-editor 6.x-2.0 and update.php
#575626: Activating Fckeditor breaks existing node formatting
#627514: Link to node icon appears not activated
Thanks to tobiasb for providing a German translation.