In the UK, it'd be a shorter list of guitarists who *don't* play blues, or at least who haven't played blues at some point in their time with the instrument! We're not necessarily all dedicated to blues, but pretty much everyone has played a bit of blues at some time.
It's worth remembering that the UK exported electric blues back to the US in the 60s. For a while in the 60s, the best blues and rock bands in the world were British - remember that Hendrix couldn't get a gig in the States at the time! :-/ So electric blues is about as much a part of the British cultural heritage as it is for Americans.
As for musicians, I'd chip in a mention for ex-Mudcatter DDW in Windsor, Ontario. Link here.
I'll also add the compulsory mention of my hero, Mark Knopfler. He's not exclusively blues, but there are quite a few blues in his back catalogue. "On every street" and "Ragpicker's dream" have some particularly good ones - the slow blues "Fade to black" on the former and the solo resonator-guitar stomp "Marbletown" on the latter spring immediately to mind.
Also don't forget the incredible Bob Brozman, who's American but now lives in Australia. I don't think I've ever met anyone with more natural groove than him!