I wasn't very optimistic before E3, but now I'm pretty excited for it. I'm not sure how I feel about enemies dropping health and ammo. I liked when ammo and health where rationed, and if mistakes where made (in particular on higher difficulties) I could really feel the struggle when I was lacking them. I also admit I actually liked the atmosphere in Doom 3, but I suppose the hate for no lights means that will most likely never return.
All and all, it did really seem to feel like Ultimate Doom (Or Duke Nukem/Brutal Doom), so I'm really looking forward to it.