Thanks for your post and the kind words. We're now on 75% and we hope we can keep momentum to raise it even higher. As Ben said not only the answered rate should go up but preferably the overall commitment of more and more developers to actively participate on the forum. MageStackDay alone will not 'save' the forum, only when we have users daily answering, voting, closing etc this forum has a change of being the awesome place to share knowledge we want it to be.
Now on a MageStackDay for April. We would love to another one soon but organizing a MageStackDay takes up a lot of time and effort. To give you an idea for the last 3 or 4 weeks Anna and I support by David Manners and Marius Strajeru have been in daily contact via chat on how to promote the event and todos for making sure the experience is a great one for everyone. Getting module vendors involved (which helped the answer rate greatly) took 4 email campaigns, sending out Tweets to every vendor and answering questions by mail. Same goes for all the Magento developers who participated. Overall this takes close to 1 or 2 hours per day.
We will surely be back soon but April might not be doable as we would really like to enjoy our evenings off for at least a couple of weeks ;)
But no worries, we'll keep the Slack channels open and will continue to motivate people to join in so every day can be a MageStackDay!
See you soon on the next MageStcakDay and of course on the Magento StackExchange forum.