(...and also permission from Eliezer, who has the right to veto this whole idea should he so desire.)
In the hope of launching a collaborative project, I've set up Wordpress sites for translations of the Sequences into French, Italian, and Spanish; and to get things started, I've put up my own attempts at translating the first post, The Martial Art of Rationality.
I'm looking for collaborators. At the very least, I'm hoping to find folks who would be willing to proofread my translations and help improve them -- in particular to help me purge them of the inevitable mistakes, non-native shibboleths, and typos with which they're bound to be infused. Beyond that, it would of course be nice to have people contribute translations of their own of entire posts. (I'll keep plugging away myself no doubt, but if I'm the only one, it will take a very long time to complete.)
If you'd like to translate articles yourself into one of these languages, send me a PM so I can add you as an author on the appropriate blog(s). Proofreading my work can be done either privately or in comments here on LW; I'd probably prefer to reserve the comments sections of the actual sites for discussion of the posts' content (in the target languages), although this isn't an inflexible demand.
Also, one would like to add more languages, of course...