Yes, it is surprising that search engines are still relying on the host location to determine what they consider a related country (in the case of .com).
I have a hobby
website hosting and I had to use a US based host for it as I knew the majority of people searching for the content for that
website hosting would have been based in the USA. It was the primary reason for choosing US hosting - however, I have noticed there is a severe lack of quality UK hosting available that has any customer service.
This is why I am at eukhost now - just trying to decide which option to go for.
Anyway, I will have a .com and the equivalent .co.uk - registered both as I intend it to be a brand name in time and for that, the .com would be more or less essential to obtain even though the initial audience will be UK focussed. The .com is the domain name people still have most trust in and for branding purposes - if it is available then purchasing it would be the wisest thing possible (as if it built up any reputation, a domain squatter would quickly seize on the .com version).