CTAN has a new package: xetex-pstricks
This package provides a configuration file to support the use of PSTricks with the xdvipdfmx output driver, as used by the XeTeX engine. With this configuration, many PSTricks features can be used in xelatex or plain xetex documents.
This package is located at http://tug.ctan.org/tex-archive/graphics/xetex-pstricks . More information is at http://tug.ctan.org/pkg/xetex-pstricks (if the package is new it may take a day for that information to appear). We are supported by the TeX Users Group http://www.tug.org . Please join a users group; see http://www.tug.org/usergroups.html .
xetex-pstricks – Running PSTricks under XeTeX
The package provides an indirection scheme for XeTeX to use the pstricks xdvipdfmx.cfg configuration file, so that XeTeX documents will load it in preference to the standard pstricks.con configuration file.
With this configuration, many PSTricks features can be used in XeLaTeX or plain XeTeX documents.