Scenario: you want to hold a brunch with just the members of the wedding party. You want the info for the brunch to appear in the Event Details section for the invited few, but no one else.

Currently there is one event per user account. Repeat customers have no way of managing multiple events at the same time or consecutively under one account. They have to use multiple accounts. This should not be the case.

Immediate ticket purchase for events that require them from RSVP-confirmed guests.

If the event planner changes a location, menu choice, etc. I want to know about it! Send me an email or something.

Some weddings don't want gifts, they want "honeymoon fund donations". Class reunions, charity events, etc. could all use donations. No need to create a donation system, just integrate with an existing one. PayPal offers donation buttons. Is there a better service?

Guests sometimes don't use the address bar of their browser to input their RSVP address. They search for it on Google, and come up empty-handed because the sites are private. Then they search for Mightyvites because they see the name on their invitation. There should be an easy way for them to get to the right RSVP site from mightyvites.com.

Planners should be able to define the order in which their locations, notices, and links details appear. I'm thinking drag'n'drop ordering in the planner left side panel.

Organizers should be able to set a date for which guests will no longer be able to edit choices.

Somehow make it easy for people to deal with their invite wording. Maybe there can be examples that are linked to (in FAQ or on other websites) or a form with sample wording in place that they can edit. (this would also help with people inputting the preferred number of lines of text for each invite design).

Another event detail where users can embed a YouTube video, Flickr photo, etc.

Send notifications/reminders to guests who have not responded by a certain date of the planner's choosing. Could be done through e-mail.