What about the site name? Most proposals have very descriptive titles, but I presume some people would prefer names more akin to what "stackoverflow" is for programming? And related to this, can we have distinct domain names, or will they be blah.stackexchange.com?
At the end of 60 to 90 days, if the site has enough ongoing traffic and enough questions are getting answers, it will graduate to a full-fledged, permanent Stack Exchange. At that time the community will decide on a permanent, top-level URL, a web design and a logo.
So yes, the site name will be "up for grabs" as I would assume that the top level URL will be:
Hmmm. This answer over here on stackapps guarantees that site_name will be fixed and never change. The sites have been added to StackApps (No access to the private beta? You can view it through a selection of the apps on StackApps - shameless plug for my apps here and here) so I would assume that the names are fixed?
Otherwise, someone at the API has been telling porkies.