Yuku has decided to "upgrade" these profiles, but they are not really out of beta-testing yet. The new upgrade currently doesn't allow the user to customize their profile. So I advise that you do not upgrade yet if you really care about how your profile looks.
You can read about the new profiles here:
There are several tutorials on that board about how you can set up your new profile. I guess at some point all profiles will convert but I have no idea when.
The only way to upgrade at this time, as far as I know, is to be "invited" by someone who has already upgraded. If you see a little gift box image in the center of your screen (as pictured below) you know you've been "invited":
Again, upgrade only if you don't care how your profile looks.