The inlays are different (dot's vs. jagged mirrored shark fins). I know that the 570ex has got some fancy material down the sides of the fret boards (it's not binding tho). It's a bit like alabone (sp?), It shimmers different colours. I don't know if the 570 has that. The trems are different too. The 570 has the original Edge trem, whereas the 570ex has the lo-pro edge. I believe they are both as functional and as stable as each other, the lo-pro is just designed so that it doesn't get in the way as much.
There are plenty more educated than me about this though. Check out
www.jemsite.com which has some info (i think) about the different trems.
Daniel C.