Mobile friendly event registration on a web site
For us, our main priority is to enable event registrations in a mobile-friendly view. A close second would be a mobile-friendly event calendar. We are fans of mobile web apps over native mobile apps. We host many events that are dependent on weather conditions, so there are a lot of last-minute registrations.
This is something we want to achieve by creating so-called fully responsive themes - so your member's (or public) website is presented differently depending on a device it is accessed from. It includes event calendar and event registration gadgets as well.
We're working on such a theme now, but I have no estimations on this matter.
Unfortunately, current (old) themes will not support responsive behaviour in the nearest future. When we're done with the new responsive theme, we will start changing some of newer older themes to be responsive, but this is going to be 2015, not earlier.