Just thinking in a wide prespective
1. consider WYSIWYG functionality. Though the plugin support html, we have to create tip content in some other editor and then paste html in the text box to get desired results. WYSIWYG editor shipped with wordpress would be an useful addition without making it fat.
2. classification of tips. So that tips can be categorized and prefix like pro tips, support tips etc. can be added automatically.
3. Integration with pro – sites and membership. some tips are likely to be related to services offered as premium services and naturally they would be useless if a person is not a pro user. (tips about setting marketpress would be useful only for a pro user willing to use this plugin)
4. Ability to dismiss tips. If an user get acquainted with services pointed by a tip, it is likely that he may get irritated or just start ignoring them. At this point user control to hide certain tips can serve the purpose to show relevant tips only, to keep them interested in tips