We could use an automatic translator to translate most of UI elements: menus, headers and other "User Experience" things, and then correct the translations in such cases where the correction is needed. This way, the creation of Spanish Stackoverflow will be much faster!
I have used an automatic translator "Google Translate" for Spanish forum for a long time, and people seem to understand me very good. Yes, it is bad for some relatively diffucult languages like Chinese, but Spanish is one of the simplest languages, so there should be no problem with using it.
I have a pen friend, we were having conversations in Spanish for a long time. I thought he is a native speaker (just some issues with punctuation and grammar), but eventually he told me that he was using an automatic English -> Spanish translator nearly all the time! So, I thought, if automatic translators are so perfect for Spanish language, maybe they could help a lot with new Spanish StackOverflow!
Proposal: Stack Overflow in Spanish