It's 5 hours for a single language on my box, and that's "make html".
One language, one make target. We have quite some languages, and quite some make targets. I had some suggestions on improving this, by having an intermediate format [without TOC]. So there would be no need to rebuild parts in the translated versions which are English. That would only work with some PHP postprocessing work and with the XSL sheets. But that would definitely reduce the time for building. It would also use the same source files for phpweb/html and probably CHM output. So it would cut on the multiple outputs and multiple languages times'. But that is just a dream solution now.
James also suggested to prioritize the languages for a short term "kind of solution". That would mean proper building for the EN manual at least weekly I guess.
After thinking about this, I would like to correct myself. 5 hours should not be one language, it is probably all the languages. :) Otherwise my comments have a ground I think ;)
Goba