You can use this vertical marquee plugin to make your text scroll upward or downwards.
New demo link
New option to add expiration date for the message
Tested upto 3.4.2
Tested upto 3.5 New PHP code to add plugin directly in the theme file.
Tested up to 3.6 New admin interface. Added few security features.
From this version onwards plugin support multi widget. If your using widget option and upgrading the plugin, This upgrade will remove the widget from your sidebar. Thus please go to your dashboard widget menu and drag and drop the widget again (One time work, not required in future)