Spoilin' for a fight
TLDR: Solomon Kane kicks ass, go see it.
Full: The casting is a little odd. James Purefoy is very, very posh indeed. "Son of an earl"-style posh although I have no idea whether he is actually the son of an earl or not. So his attempt at a West Country accent (very piratical) was somewhat grating but not actively painful. Okay, that's out of the way.
The storyline is faintly hackneyed but this is a sword+sorcery flick so what do you expect? What raises Solomon Kane above 95% of sword+sorcery drivel is twofold: The setting and the direction.
The setting is the conflict of Puritan England and although it's understated, it works very, very well. The lack of medieval peasants and knights doing knightly things helps a huge amount. The direction... well, the writer/director has a very strong background in horror and the whole thing is done as a horror movie. This works unbelievably well.
The acting, while great, is not a breaking point. It's actually not uncommon to get some very nice performances in fantasy films but they're usually dragged down by the setting and the direction. This one wasn't, so the acting really did shine. Purefoy himself is (although I say it grudgingly) excellent, there's a lovely turn from Pete Postlethwaite and Max von Sydow's stab at a Somerset accent as Kane's father is rather endearing. And the big surprise for me was Jason Flemyng as the evil sorcerer, a quiet and definitely spooky showing made all the more disturbing by the way he quite deliberately played the character as very sane.
This film is extremely violent, although there are long stretches where there's only really dialogue and this allows the actors to shine. The violence, however, is not gratuitous and was choreographed quite superbly. CGI was used only when there really wasn't any alternative and was pretty seamless throughout.
I very strongly recommend this film and fervently hope that those responsible for the upcoming Conan movie have been taking notes. THIS is how you bring one of RE Howard's characters to the big screen. Leave Arnold at home.