I'm sure it'll be fun. It's hard to make Caesar boring (although I would have thought the same with Alexander before that disaster of a movie). I guess it'll be like HBO's Rome only starting a bit earlier so you'll get a lot of Roman power politics and fighting.
Assuming the spoiler you are referring to is:
While I guess it's necessary to make the spinoff, I hope they cast a good actor to play Crassus too because, for Spartacus, that's the Roman who was actually the enemy and, although he's kind of forgotten in things, he was just as important as Pompey and Caesar at one point.