After installing the Global wordpress translation plugin, I have been subjected to constant Forbidden 403 Errors on all the translated pages. Though caching is essential to reduce the load on these translation services and prevent your blog from being blocked as spam, even 24 hours caching failed to work and a few pages that worked made no sensible translations. Human translations are emerging as a more feasible option.
There are so many WordPress translation plugins available, most of which use the Google translation services or Yahoo! Babelfish. Connected Internet says his site could be actually getting less traffic rather than more.
Getting humans to translate your blog posts in multiple languages is a professional job, a continuous one on a daily basis and cannot be expected to be free. Many blogs have started hiring professional translators to create translated versions of their blogs.
Weblog Tools Collection was recently looking for blog translators in Spanish and French. The translators were expected to translate all (new) posts into their respective language and make a daily commitment to posting changes and updates, moderate and answer comments and post any new material relevant to blogging in general and WordPress in particular. Some remuneration will be involved. I see 2 language translations already live.
Ghacks is looking for translators and is willing to pay 50% of Google Adsense revenue that the translated pages generate. The translators need work on a daily basis to translate everything that they write into the other language. I see 3 language tranlations already live.
Human translation is the best option to make sensible translation of your blog webpages (if you can afford it). Translators have a huge revenue option opening up and I predict this will grow in a huge way in the near future. I am sure WordPress translation plugins authors are busy figuring out a way to better caching and better and more readable automated machine translation (I hope they do this soon before users start switching).