Xombie, I see you making a lot of valid points (albeit speculative), but bottom line is, until you actually EXPERIENCE the Deus Ex 2 engine/HL2 engine/etc., you're basically comparing engine hype to engine hype. Have you experienced the "complex AI" in Deus Ex 2/HL2? Previews of RtCW and Unreal2 said the AI was going to be complex, yet it was anything but. What little details we do know about Doom3's engine (i.e. realistic physics) ended up integrated in these other engines too, but until you see proof of timelines for engine development, isn't it just a chicken/egg argument?
Your statement about "Deus Ex 2 is improving upon every single shortcoming of Deus Ex" is straight from the developer's mouth. Is that nothing more than a hype statement as well? I want Deus Ex 2 to knock my socks off, and Deus Ex 1 almost did if it wasn't for some strange clipping error that caused me to die when walking through a doorway (still waiting for support to answer that one BTW), but until I try it, all I can say is that it sounds good or looks good.
What's to say that this Doom3 video isn't rendered in some way to up the frame rate to look better for E3 presentation? It's a promo bit pure and simple to get people to drool. The promo video doesn't cost $50, so how can you complain already about paying for content?
Even so, arguing over an engine's possibilities is pointless. Half-Life's engine, Quake3's engine, Unreal's engine are still being tweaked and redefined to this day. The point is, does it effectively do what the developers wanted it to do and does it put a fun product in the hands of the gaming community? Given id's track record, I'd say they know more than a little about what gamers are looking for. Whether they succeed more than Valve, Ion Storm, etc. after all is said AND DONE, remains to be seen. If you're skeptical of id, OK- we get it- we won't look for you at the store when it goes on sale...just stop flooding Blue's bboard space repeating yourself about textures and unoriginality in a 30 second promo video.