.co.uk appears regional: not smart branding-wise. consider The Economist mag.
I am not a regular user but have come across the site on ocassion, if linked to from blogs etc. In fact I had to register to post this comment. So perhaps as an infrequent visitor, my take would be novel.
The most typical scenario for my landing at theregister has been when I have gone through google news. When I see that it's .co.uk, I figure it'll be some sort of regionally-specific view on whatever topic is at hand.
Clearly this is not the case, and theregister is of value to any English speakers around the world.
I think the best point of reference would be Economist magazine. UK based, but globally relevant. the .com in their URL is neutral... to anyone unfamiliar with the magazine, .co.uk may have given the impression of being UK-specific, and may have negated millions of clickthroughs.
Some may "whinge" (as y'all say up in them there parts) that dropping the .co.uk is unpatriotic... foreign Anglophiles may suffer a loss of split-second masturbatory elitism... but at the end of the day I doubt pageviews will suffer from the switch.
If it does nothing but to appear neutral and non-regional to potential new users, I'd say .com would provide nothing but upside.
Best of luck
Mark B
Los Angeles
Biting the hand that feeds IT
