Some of you already asked this question - how to move to the new members area (same one int this site - with the new profile page, members page etc.), with an existing forum?
So actually you can do it now :)
Go to your editor
Click on the add panel (+) icon
Go to 'Members' tab
Install the new members area
Delete the 'old' members page you have in your site (so you won't have duplications), you'll see now 2 in your menu - but you forum will now work with the new one.
What if I already have members area installed?
Delete your forum (don't worry your data will stay)
Install again the forum from the app market button
If you have any question - please let me know.