The whole notion of waiting for the next one...is like waiting for the perfect woman when you have a perfectly good one in front of you. Better things will always come out, fortunately with phones you can change it again a year or two if you feel like it'll be outdated.
I had a D1, I HAVE a DX, just finished ordering my TB.
The reason I ordered it? I played with an inspire 4G and there was no way I could keep playing around with Motorola motorblur, Sense is just beautiful in every SENSE. Smooth. Great. I don't care about dual core, don't care about triple core, won't be using all those cors anyway. Bionic will be the first dual core phone so it's untested technology.
The snapdragon processor is well known for how well it works, they compared it to the iphone's ios and it beat it, this one is a SECOND generation snapdragon so it's improved.
A car that has 250 horsepower won't always be faster than a car that has 200 horsepower. It's all about engineering, and this phone was engineered to near perfection IMO (except that damn battery life)