Btw, apart from the issues of regional relevance (e.g discussing developments in Europe, avoiding US-only services, etc) there are some cultural differences too, which a European HN-like site might alleviate a little.

As a European I find a lot of american's grasp of economy and politics extremely naive (and if I read about Ayn Rand again, I will smash my monitor). Also, the sometimes extreme political correctness (which comes natural for some people) leaves a sour taste in my mouth.

Now, those are peripheral issues, true, but they occur a lot of times in HN discussions.