.co.uk is the only way to go
A few points or rather recommendations.
1. Stick to writing great articles.
2. Sack whoever started this idea in the first place, they are probably in marketing.
3. Go to the pub.
4. Produce a dossier stating that a .com address would in fact lead to an increase in terrorism, use something like terrorists will be able to mount a nuclear strike in 4 seconds through a .com address rather than the trusty .co.uk.
5. Sleep well at night knowing that theregister.co.uk is not only the right choice but rather the only choice for the people of the world.
6. Don't assume all of your .co.uk readers are in the UK. So no naff auto detection please. I'm a brit in Singapore and would prefer not to end up at a us/international version of the site.
7. Work out how much money you have cost the IT industry from people reading this article and posting comments :D
8. Go to pub for a well deserved drink.
9. Ignore the majority of public opinion and go with theregister.de just to really p*** everybody off.