Widget Entries plugin by marquex creates the Widget post-type in the administration area to make easier the edition of the text widgets, and it also register a new widget to import the widget entries easily.
You can format your widget with the WordPress editor.
You can upload images directly to be shown in your widgets.
You can have widgets drafts.
You can use shortcodes inside your widget.
You can get back to a previous version of your widgets thanks to the revision feature.
You can export your widgets contents.
Use php scripts inside the widgets.
download and info: http://wordpress.org/extend/plugins/widget-entries/