I've gotten Karl's DPS working on AOLserver/Solid without hardly any real work... I'd expect it should install cleanly into the latest OpenACS just as it would with ACS Classic. I didn't have a lot of luck initially with his 0.4 tarball--instead, I downloaded the latest sources by browsing it online and then stripping out the four or five lines of HTML formatting at the top and bottom.
I know Karl's system is only one of several different ways aD is looking at to separate out presentation, and I have no idea what the others are, but ACS 4.0 will be pretty slick if Karl's system is used.
Where I work we've been using it now for about a week and our "content" and graphics people feel newly empowered, I don't get pestered to go in and modify .tcl code as much. I'd actually hope aD would release it as a completely stand-alone system for AOLserver, in addition to rolling it in as an option for ACS Classic.