I am not sure what methodology the Observer line up uses to establish the ‘powerfulness’ of a blog but perhaps I shouldn’t scratch it given that Samizdata.net ranks 39 on their list of the world’s 50 most powerful blogs.
But I will given that our ‘blogfather’, Glenn Reynolds is missing from the list. And probably a lot of other blogs that I’d consider more influential.
To me it has always been about who reads your blog (and shares your ideas further), not how many that makes a difference. Of course, having an audience to start with helps.