Google is allowing the world to test the latest major changes to the way they carry out searches. This is being referred to as the caffeine update and could be quite a big change. The test environment can be found at:
This is bringing back searches from the Google .com site but if you want to know how your page will look on the UK serps you can add &gl=UK to the end of the query string and hey presto you get the UK version. This also works for &gl=ie in Ireland so I’m guessing you could transpose any tld to get the relevant results for you.