I think that if Blizz wanted to announce its game using a European site, mag, and whatnot, it would use an English one. For the simple reason that most Europeans know at least elementary English, while languages like German or French are still behind in terms of the number of speakers.
It's not as much the European market as the UK market. In terms of games sold the rest of the European countries is lacking.
Well Europe is not just UK! The biggest gaming market in Europe is the german speaking market with germany, switzerland, austria and lichtenstein.!! and speaking of games being sold outside UK --> think about sweden, norway, finnland!! or russia (though they rather download cracked games^^) and yep the european gaming market is bigger than the USA market.
I agree with you that most of european people are able to speak english. This is not an argument against a special coverage by a german magazine, though. Anyway I guess that pcaction is just a bit a "attention whore" as the mag itself is more or less a not so serious one.