Ok, let's make for everyone the list of what has been added in that wasn't available before, and could NOT be added with ...
1-Disaster
2-Totaly new victory conditions
I mean, what more do you want? Not only are they adding stuff we could mod and improving the product, but they're also adding in totaly new features that we could obtain in no other way, namely the disasters and the victory conditions.
PTW was lackluster in single player addition (though still not bad), and of course the multiplayer was bad. Conquests definitely does NOT look that way.
And anyone who think the victory conditions and disaster should be given to us for free as a path is seriously delusional. There is no ground to ask for those things for free (unlike multiplayer and some of the PTW editor improvements - we were told we'd have a functioning editor and MP in PTW), as they were never ever mentioned for Civ III (mentioned by the designers et al, that is) - As far as I know, no one expected either to show up before Civ IV, if even then.