Since my experience with RPG's is limited to Kotor and most of the NWM official campaign, I hope that the game isn't harder combat wise, but harder in terms of problem solving. When I first got Kotor, I had a hard time with combat and stats (and I am still not too proficient). I don't want to be able to beat the game just by running around and killing everything that is hostile.
I think with all of the new combat features that we will see more combat in order to use all of the feats, powers and stances that we will choose. I don't think that it will be any harder because (as someone already stated) as we get higher in level, so do our enemies.