SVC,
Unfortunately those listings wont last... but that is not a totally bad thing...
Your new pages were found by Google's daily running bot(commonly/previously known as FreshBot), and they were 'looked at', 'grabbed' and listed in what the bot thought was a good place to put them..
Google's bots will come back and look at the pages again and give them a 'better/deeper' look, and then they will "fall" into their true rankings...
Your good ranking is because Googlebot found fresh "content"... and as we all know Google loves fresh "content".
It has little or nothing to do with the IP/host etc.
Keep an eye on those pages and where they rank in Google and it will give you a good idea about how it all works.
This tool can help you keep track of them. -
http://www.nichebot.com/ranking/
Remember! - no tool does the work for you, no tool is 100% accurate, Google does what
IT wants to, when it wants to.
[As always - this post is an opinion based on experience and should not be considered fact unless properly supported by legitimate references and examples.]
DD