I stopped by the game shop and picked up the Orcs & Goblins army book the other day:
...as every other blog & web site has pointed out, this is the first army book / codex that Games Workshop has printed as a hardback, and in full color throughout:
...I do have to say, it's a gorgeous book - since painting & modeling is the majority of the hobby for me and I'm always looking for inspiration, my favorite part of the codexes are always the color photos of the painted models. I've heard a lot of grousing from the tournament players about the hardback being less "travel friendly", but I've had lots of problems with my softcover codexes falling apart, and I tend to treat them pretty gently. I'll gladly take a few more ounces in weight and a few more dollars in price, if it means that I don't have to laminate the book with packing tape to hold it together, like I've had to do with the last few 40k codexes I've bought.
As far as the rules / changes - I have no idea. :-) Sorry, but I'm brand-new to fantasy, having just acquired the beginnings of an Orcs & Goblins army, and haven't even really delved into the ruleset at all yet. I've heard some people complain that the changes were very, very minor, and this book is almost a reprint of the old book - well, I didn't have the old book, so I can't speak to that...