My copy hasn't arrived yet, but from all the available info it's just UAE on Linux, even if it is a "live" Linux distro.
This has good points and bad ones. The good points are compatibility with anything supported through Linux, the bad ones are incompatibility of AmigaOS side drivers which cannot be used, unlike Amithlon. Native x86 code for Amiga apps will also not work.
So, in the absence of Amithlon/Umilator or any follow-up, AF 6.0 is as good as it gets, but it ain't a replacement. It's not the "new generation" Amithlon or anything like that.
There's the ANN thread
here, with a few comments from Bernie on the differences between the two.