Im 100% up to date with it and still love it.
Its actually based around the Sagas of Ragnar Lodbrook isn't it? Only loosely however, so obviously there's some pretty massive interpretations in the interests of entertainment. So you can kind of tell what is going to happen in the future, but its still a good watch.
Ragnar, King Aella, King Horrik were all historical characters I believe.
I know a little about the saga's so I've got an inkling as to what happens, but it'd be interesting to see how the tv show plays it.