Not sure if I'm going to add anything constructive here or simply feed plankton to the fail whale, but I got a 0002 version EVO on launch day. It had a plasticky back battery cover that failed to stay firmly shut (I could slide my finger along the gap on the side lengthwise down the phone and it'd pop off), it also suffered from the "grounding" issue (which I doubt I'd have known about until I read about it here), but most importantly it had terrible light leakage UP onto the LCD rather than around the capacitive buttons. In addition, those capacitive buttons would remain on at all times, regardless of the conditions: dark room, light room, wherever... just ever so faintly, but enough to be noticeable.
Anyway, I got a replacement from Radio Shack which is 0003. This one doesn't have the grounding issue or any light leakage at all so far, but we'll see how long that lasts. Battery is the same type as the 0002 one (plain red, no gold bands). It also has the more 'rubberized' softer back which stays on tightly and snugly and is much harder to take off (can only be removed now using the little recess in the top, no gaps lengthwise along the phone's back), a less recessed power button as someone else pointed out, and a Samsung micro SD card.
Now, I don't know what difference this all makes to the arguments here -- evidently people have versions of each that work just fine, but so far, I'm noticing a considerable quality improvement with the 0003 version, however, I doubt I'd have even noticed these small cosmetic changes if my original EVO (0002) would've been perfect from day one.
As far as software, performance and all that stuff, no differences at all. Still love this phone, glad I got an EVO, but would recommend people replace their faulty ones if they're truly concerned... evidently there are better ones out there.