The text-to-speech feature will allow you to select the dialect for languages like English, Spanish, Portuguese and Chinese. It's nice to compare American English, British English and Australian English.
There's also a phrasebook feature that could help you learn some useful phrases and words in a variety of foreign languages. Another disabled feature is a dictionary view, but it's not clear if it only uses Google's dictionary data. Google could also monetize the service by including contextual ads.