The Pottermore Insider blog has been updated with some new details about the experience. They answer some more questions about dueling, potions and more!

‘… It’d be nice to know IF Wizard Dueling will be available to beta testers again. I don’t care when, just a yes or no.’
Yes! We know that you like Wizard’s Duel – a lot. This section of the site has proven to be immensely popular and we’ve been making a number of improvements behind the scenes to ensure that it runs as smoothly as possible. We just need to finish making and testing our changes.

‘potions take way too long to brew #pottermore :/’
We’ve noticed that people are finding that the potion brewing times are too long, so we’re making some tweaks to these. You’ll see the changes implemented in the coming weeks.