I believe the tour got postponed before(?), but X JAPAN will be performing in Paris on November 22, 2008 at Palais Omnispots de Paris Bercy.

From Japan Today:

Rock band X Japan will start its world tour in Paris on Nov 22, their agent said this week. The group had been delaying the tour since leader YOSHIKI suffered pain in his neck and hands and can’t easily move.

The agent said YOSHIKI’s doctor has given him the green light to tour from November. The world tour will kick off at the Palais Omnispots de Paris Bercy, and the band will tour other European countries, the United States and Asia with schedules to be announced, the agent said.

And also confirmed on X JAPAN UK:

X JAPAN will perform in France on November 22nd, 2008. The concert will take place at the venue Bercy in Paris.
More information will follow soon.

Good luck to anyone who is going! And if anyone has anymore information, please share!