Well Dolphin 7.0.9 was finally released today (January 24th, 2012) after 2 beta releases...Go figure that one out. You can read more about what is new and all the details here in this post at Boonex:
Dolphin 7.0.9 Released
It seems to address mostly fixing bugs and other issues, but also Boonex mentions security fixes too. So keep that in mind. Other than that jQuery is supposed to be using a minified version now. TinyMce, Html Purifier, and Phpids were updated as well.
This was just recently released so there isn't too many topics surrounding how well the upgrade went or if anyone has had problems with the upgrade. Keep an eye on the Boonex Forums for more details.
I shouldn't have to mention this, but before you even think about upgrading backup your entire site, your files and database.