It's a Google page and after hunting around on this site I understand it's one of their many datacentres.
But my question is, is it a good thing to be listed in this index? Does this mean my site's been ignored for the main index? Or will it migrate there in time? And if so, how long does that generally take?
Yes, it's a good thing for a 1-week old site to be listed in any Google data center. There's no certainty about what the future will hold, of course, but it is quite likely that your domain will soon be found on other data centers.
This IP is a specialized Google Search of some sort. Just a guess, but it may be associated with a free wi-fi service they are providing somewhere.