I'd like to know what LuaTeX offers in terms of graphics: I'm mostly interested in pstricks and tikz/pgfplots. Could it help tikz to run faster? Would it help tikz to handle 3D non-parallel figures? (which is not available yet and is CPU consuming). What could it bring to the pstricks package users?
In principle, LuaTeX offers more flexibility, and in particular more speed, for Tikz,
pgfplots, etc. This is because the work (especially floating-point maths) is going to be much easier to do in Lua than in TeX. On the other hand, PStricks uses the PostScript language for the hard work, and it already offers native support for a lot of this work. So there is much less scope for assisting there. (Herbert may have more to say on PStricks, I suspect.)
Recently the developer of tkz-euclide, tkz-graphe and some other graphics package has announced on fr.comp.text.tex that he will adapts his code to Lua (now it's gnuplot who does the job to calculate coordinate).
P.S. I would like to do a comment of these «answer», but i haven't enough reputation yet to comment