Google's John Mueller had an early hangout this morning on the topic of internationalization and Google search. I find the topic to be fascinating, mostly because I don't have direct experience implementing an internationalized site specifically around SEO purposes. The topic of href lang versus geo-targeting and then all the technical issues with both, is pretty fun.
Here are the slides from John's hangout this morning on YouTube:
Here is the hour long hangout:
Forum discussion at Google+.