Google's officially launched voice search in the US. You can actually play with it in the UK by going to Google.com and staying there (ie; overriding the Google.co.uk redirect).
I've found the voice search to be quite good - even though I'm often very hard to understand. I don't find it to be quite as good as the voice search on my Android phone though. That's a little hard to explain unless it comes down to microphone quality and placement.
It's not often an error message gives me a new phrase. Google has. "Speech servers" is a fantastic phrase. The idea that there are big machines, or clusters of Google-esq processes, waiting on the end of VoIP tech analysing comments is sci-fi to the core.
Google are putting some clout behind their voice campaign. In the UK we've seen poster campaigns to promote speech recognition on Android. In the States there's a video campaign (ad below) to promote the desktop speech search.