Having just complained about myself that I'm strictly a reactive poster, I'll start my very first thread.

So, I just got Dunnington's _Attacking with 1. d4_ in the mail.  It was a birthday present; I never play 1. d4.  But reading it, I began getting excited at the prospect of playing 1. d4 like a raving berzerk madman.  You know, the reason most of us play 1. e4.   

So, how big a transition am I looking at trying 1. d4, me, a guy who's played 1. e4 his entire life?   

There are a few good transpositions I can make.  1. d4 e6 2. e4!, or 1. d4 d6 2. e4!  Ha ha ha, you picked the wrong guy to bluff into an e4 game!  Or I was all excited when I realized that 1. d4 Nf6 2. c4 c5 3. Nf3! and I'm practically playing a Sicilian.   

Otherwise, the e4 QGA, the exchanged QGD, the f3 Nimzo, the Four Pawns Attack KID, the Bf4 Gruenfeld, is a repetoire like this an entirely different game than the one I've been playing?