I've written up today's release in some detail at Search Engine Land.
The service allows users to text ChaCha (242242) and to essentially ask any question about any subject, which makes it more flexible that the current crop of free DA services. ChaCha's many human guides respond in the same way that they do on the desktop. However, in mobile, you get a single answer (via text).
I asked the following questions in testing out the new service:
Overall it performed generally well in response to these questions. There will be a client advisory coming out shortly with more detail.