As far as I know it is not (yet) possible to use pstricks directly with luatex (-> pdf) as for example in xelatex.
Are there any plans to implement this in luatex in near future? If so, how is the state of this? If not, what are the problems?
Naively I think it should be possible to make luatex recognize a pstricks environment and start separate thread which compiles the pstricks picture and includes it automatically as a vector graphic into the pdf.
Given that luatex is the successor of pdflatex, I think it should be a very desirable goal to have working pstricks and pgf in one document out of the box with one engine.