If you use the CKEditor through the WYSIWYG module then you can normally turn on the editor for any textarea by selecting the ckeditor enabled input format. This was broken in simplenews_template. Attached a small patch that "improves" (actually it looks more complicated) the form code so it works with CKEditor.
Using this patch does not even break existing settings.

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simplenews-proper-format-field-for-ckeditor.patch2.56 KBmiiimooo
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