We are using google translate to translate conent on our website - a base of categorized articles. Of course we include an information regarding that translation is done using Google Translate service.
The question at the moment is, if serving translated content (which may in some cases seem like spam, as not everything is well translated using automated services), we won't be blacklisted by Google Search services as spammers?
No, serving auto-translated content is not automatically labeled as spam by Google. But as you appreciate, it is best to get those pages edited by a native speaker ASAP. Otherwise, the pages are only of minimal value to a visitor.
I have heard of websites getting into ranking trouble by using a plug-in that auto-generates many languages via online services. IMO, that really IS a spam attempt and it doesn't deserve to rank. I know that as a search user, I don't want to end up on a page like that. And I usually don't - Google doesn't seem to rank them very well.
But if you are serving the translated text directly from your servers and for a selection of languages that your site really wants to accommodate, then you should be OK.
<added> If your main articles are of value, then I would tread lightly with an auto-translation roll-out. You don't want to overwhelm the presence of your good content with content in other languages that is of marginal value. When the translations are worthy of someone linking to them, that's when I consider going big with them.