I just got a dedicated server (in the US), but the IP is registered in Germany.
If it's good enough to rank in the www.com results you will not have a problem, however some other SE's are offering just US results and then you will have a problem since you will not be viewed as US based.
The new MSN has skewed things terribly and is all over the place however Altavista does offer this on the search bar.
IMO this is going to be offered more and more and we shall all be chasing around for geo-targeted hosting.
What do you think?
Great new business opportunity for the host that can!