I'm glad I passed on this game, I am a huge fan of Butcher Bay but this game didn't get good reviews. The Dark Athena campaign pretty much sucks(according to my friend). It's just a shooter and the graphics aren't much better than the original.
Dark Athena is pretty much all stealth and melee until the second half... it also looks much better than the original game, and has a very cool and unique art design that fits the narrative very well. The only thing it really lacks compared to Butcher Bay is the "walking around talking to people" stages... while it has a little of that, it's much more limited.
Still, I found Dark Athena pretty awesome, and as a matter of fact it's probably my lead candidate for game of the year at this time. Butcher Bay was nice to run through again too, and is still an amazing game.