After typing a text using the integrated TinyMCE editor, you want to apply Headings effects to one line and all the lines are transformed.
Similarly, if you want to apply a List effect to a few lines the whole text is considered as a single paragraph.

Here attached are some snapshots of the problem.

A sample of a normal behavior is demonstrated at: http://tinymce.moxiecode.com/example_word.php?example=true

The issue seems to be caused by these lines in the file wiki-textarea.vm:
force_p_newlines: false,
force_br_newlines: true