Mentioned this to yano in IRC. Another user mentioned a possible reason why it still works:
yano: jenni is pretending to be Firefox when using translate. Maybe that has something to do with it
possibly
sbp and someone else figured it out
It's pretending to be Firefox 2 though, you should upgrade your fake user agent!
According to https://code.google.com/apis/language/translate/overview.html the API hasn't been free for months. I don't claim to know how it works, but the change obviously hasn't affected it. Closing the issue until it actually stops working.
As mentioned by @ubertaco in issue #6, the Google Translate API is no longer free. We'll need to move to something else.