I'm working on a fairly large site, which has multilingual options, but not correctly implemented:

Currently:

- Example Domain
- Example Domain

Looking into doing this instead:

- Example Domain
- Example Domain

I came up with this structure by doing some best practices research on SEOmoz etc. - now my question is, will this have an effect on our rankings and how immediate will the effect be (probably after google has re-crawled the page).

Are there any case studies you know of where a person/company changed the url structure and had good results?

I posted this on Pro Webmasters Stack Exchange as well, but I'm not sure whether I'll get a good answer there.