There's one challenges that a website might run into that wasn't addressed in the article -- the difference between targeting a language and targeting a region or country, and how those two goals can get tangled.
I know of websites that have done a good job here by using their URL structure to include two signals at the directory level, one for the language and one for the country.
So for instance, example.com/de/ch/page.html would indicate German language content targeted to Switzerland, and example.com/en/za/page.html would mean English language content targeted to South Africa.
Webmaster Tools allows the site owner to create separate geo-targeting for each subdomain (something that many webmasters do not yet appreciate) so this dual directory approach can often be a help in keeping things straight. As Mueller points out in the opening sentence, "...a majority of users surveyed feel that having information in their own language [is] more important than a low price."