Well yeah, it was sarcasm (for which I apologize), it's not good to expose this to your users. When does Google do this, by the way?

One example is this server, from which my browser just requested from youtube: http://r5---sn-vgqelnek.c.youtube.com/

URLs used for asynchronous requests seem much less important. The original comment's point was about outlook.com redirecting the actual url of the page (the one in the address bar) to a data center specific version.