A WebmasterWorld has several reports from non-US based site owners saying their rankings in the main USA based Google.com has dropped from the first page to page five or beyond. This is not just one report from people complaining, there are even those with US based sites who are delighted about the apparent change in how Google handles non-US based sites (i.e. not hosted in the US or containing a foreign TLD).
Here are some negative reports from the thread:
One week ago the site ranked again in top 10 for the USA visitors. It lasted for 3 days and then it dropped again to #60+ only in the USA. It still ranks in top 10 for the same terms in all other countries.
For example my site ranks #6 on google.com for the UK IP addresses and it ranks #56 on google.com for the USA IP addresses for the same search terms.
Here is a happy report from the thread:
All I can say is FINALLY! Our sector had been dominated by .co.uk and .au sites for ages - absolutely useless to US and Canada users, as none of the companies sell in these countries.
The changes I'm seeing are all .co.uk and .au sites (previously 6 out of 10 were of these extensions), are gone in google.com, but show in google.co.uk.
Can't make everyone happy, can you? These reports started trickling in about two days ago, on January 29th. About the same time I reported that Google began implementing the geotarget data from Google Webmaster Tools.
Forum discussion at WebmasterWorld.