We had a pretty good debate over at Gamespot about DX3 and much can be gleamed from the trailer they released about a year ago. There is about 1/2 second in the clip that shows flashes of (possibly) JC's earliest childhood visions of his mother and father worried and shes pregnant with (possibly Paul Denton) all the while riots erupt in the streets and politicians rail against "Augmented humans". I'm not a fan of prequals but I must say they certainly have set the stage with so many interesting plotlines that should answer some nagging question about how the Denton boys got their start.
I agree DX1 was far superior to it's sequel and I never did play the PSX or whatever console version they tried to milk but I heard it sucked.
BTW does my Avatar look familiar? It should it's the Speed Augment from DX2 (and about the only cool thing I got out of it.)
I can't wait!