First International Workshop on XQuery Implementation, Experience and Perspectives
Daniela Florescu from BEA has put out a call for Whitepapers. I'd love to go, but its too far and too far out my job scope.
SQLJunkies own Michael Rys is on the program committee, so I bet we'll get some good blogs from there at least.
http://www-rocq.inria.fr/gemo/Gemo/Projects/XIME-P/