I've been using this for a little while. It's pretty cool, although I always find it humorous that questions about Python (the language) get categorized as 'reptile', but then actually get routed to someone who knows about the language after all.
I find this approach really exciting. The fact that it builds into existing communication channels is very very cool, and the idea of a scalable real-time service is powerful especially for mobile. I like the idea of more services embedding directly into my core communication -- chat, phone, email.