tedster - 1:59 pm on Jun 17, 2011 (gmt 0)

Why would Google replace the original URL in the SERPS?

For the basic reason that it actually was the query term. My assumption is that this is an algorithmic change to help improve click-through.

We know Google rewrites titles and description snippets based on the query - this is the first I've heard a report about rewriting a domain name.