Multilinugal error messages have now been implemented on the Wikimedia squids. I would like to thank everyone who helped to make this a reality over the past couple of weeks. I was keeping a running list of everyone who had helped, but I lost track of everyone :)
Here is an incomplete list of those in IRC who helped me with translations: taw, Mackowaty, WarX, SuiSui, aoineko, Submarine, Rama, Frieda, Quistnix, galwaygirl, Fenix, mnemo and avatar. Everyone's help has been greatly appreciated. :)
Particular thanks must go to fuddlemark for extensive Javascript help, and to Jeronim for implementing the new message across the squids.
Note that I have removed the link to OpenFacts.berlios.de, which was getting overloaded as soon as Wikipedia went down. I have also removed the link to the "offsite donation page" at Angela's request. The French, German and Japanese messages direct those people to that language's IRC channel.
I hope the community likes the new error page. Well, they'll probably hate seeing it, but I hope they feel comfort in the fact that it's now a much prettier error message.
~Mark Ryan