I think more so than ever the army has the tools to run lists of just "big dudes", with Soulstealer Carrion helping out on objectives, and Stalkers/Immortis being such great picks(Morghasts to a lesser degree as well). Those bigger miniatures is what makes me want to collect OBR in the first place.
But it makes me really sad that there aren't any generic Katakross/Stalker/Immortis sized heroes in the army.
Don't get me wrong, Katakross is an amazing miniature -and his rules are great now. But when I'm hobbying I like to make my armies "my own", and come up with lore for my units and stuff like that. I'm sad I don't have a thematic hero to lead my army if I was going to make an army like that.
On a less dour note I think the new book looks great. So many more ways to play the army now, and so many more viable subfactions!